Put together a cheap striper setup to keep in the car. Reel is the sargus 4000. Rod is a sojourn. all together only cost me $75. Going to use braid I'm pretty sure or maybe fireline. Should I go for 14 or 20 lb for fireline? I've never used it before. I would normally probably put 20lb or 30lb power pro on it but I kind of want to try something different.

At least 20lb PowerPro for me.  It works.  No need to change if it works in my opinion.

The only thing keeping me from not just spooling it up with powerpro is that a fair amount of people online are complaining about the way this reel lays line and suspect that it might cause more issues with lighter, limper braid. I got it anyways because it still seemed like the best option for cheap money overall. I'm going to leave it in my car so I don't want to leave anything expensive in there. Fireline seems a bit thicker and stiffer which might not cause as many problems. Who knows though...the internet is full of misinformation. I will say, I've used powerpro plenty and never had issues with wind knots even with much lighter line (obviously not on this reel of course). I always close the bail by hand and I pay attention to the line which might be why. I figured "hey...maybe this is an opportunity to try out something new" and avoid a potential problem (which may or may not even exist anyways).

i would ditch the braid and use 15lb mono, but thats just me...

I use a lot of 20# mono on my surfcasting reels but mono really wouldn't be the best for this setup. First is you couldn't fit much 15lb mono on that reel at all. Another reason is that this is going to stay in the car.....mono isn't the best line to leave spooled on a reel sitting in the sun in a hot car all day long.

Are you talking about fresh water or salt water?   Casting from a boat or from shore?  This alone will change your setup.  If you are dead set on not using braid or mono, the Izor line would be my choice - 15-17lb. or PLine flouroclear in 15lb.

I personally like to use 17 or 20 pound test... mono

The sojourn blank for about $29 is pretty darn good, mine is a heavy 12/25 lb with a cabo 30 reel and 20# braid, bear in mind it's a freshwater rod and I've replaced a few guides due to corrosion a couple of times.  This is one of my barracuda outfits, I do have another with 14# mono line, more line capacity reel but on a mh rod.  Being in Florida I no longer fish for stripers, but have spent much time in N.J and on Long Island catching them, so I'm familiar. 

On a 4000 sized reel I'd pick braid 95% of the time, the exception is when I'm using lures that rotate a lot a put quite a bit of line twist on, closing the bail by hand will not prevent twist, only loops caused by your line not being taut on the first crank.  I'd probably use 20# braid, should have no problem with your average striper which may be 10-15#, when you hook that 50 pounder it's time to see what you are made of.........lol.  The key is to get past that first run, then ya got them licked.

The sojourn blank for about $29 is pretty darn good, mine is a heavy 12/25 lb with a cabo 30 reel and 20# braid, bear in mind it's a freshwater rod and I've replaced a few guides due to corrosion a couple of times.  This is one of my barracuda outfits, I do have another with 14# mono line, more line capacity reel but on a mh rod.  Being in Florida I no longer fish for stripers, but have spent much time in N.J and on Long Island catching them, so I'm familiar. 

On a 4000 sized reel I'd pick braid 95% of the time, the exception is when I'm using lures that rotate a lot a put quite a bit of line twist on, closing the bail by hand will not prevent twist, only loops caused by your line not being taut on the first crank.  I'd probably use 20# braid, should have no problem with your average striper which may be 10-15#, when you hook that 50 pounder it's time to see what you are made of.........lol.  The key is to get past that first run, then ya got them licked.

Yeah, for $30 the sojourn seems like a real good value. Since they advertise the heavier models as light saltwater use they should probably change the guides on those to something a little more resistant to the salt. For $30 you won't hear me complain though. I got the heavy one also for throwing larger bucktails and artificial eel rigs with it. 15#-20# mono is what most people use around here (I usually run the 20lb big game on the larger reels because it's cheap and it works) and the 14lb fireline should be around the same strength but let me run more line than the mono on this smaller reel. I'm going to give that a shot. I know it's a love/hate line but I figure it's worth a try. If I don't  like it I have enough 20# powerpro to spool it up with later.

You've got the rod and reel, line can always be changed, experiment to see what works best for you.  One negative I have with mono or copoly is coiling, even 14# will do that on a 4000 reel.  What I do to combat that is soak my line in warm water before spooling it up, then I don't over fill the spool, my reel ( off the top of my head) may hold about 160 yds, I put about 120 on it.  I ALWAYS troll out my mono either before my outing or just after I've finished.  You want to use the lightest mono you can get away with, understanding your drag and how to play a fish is of paramount importance, your line and knots will not fail if done properly, excluding a few exceptions of course.

You'll probably be fine with any of those choices but without knowing your location and style of fishing it's difficult to give good advice. Is this surf or boat? Ocean front or backbay?  

 

Fireline tests particularly high above it's stated strength. I think 14lb fireline tests out around 30 if I remember right. On that reel 14lb fireline is your best bet if you want a fused line, and it looks like that's what you chose. Don't worry if it gets a little fuzzy, that's not a problem.