I fish out of an Old Town Salty PDL. I currently run a discontinued Garmin Echomap 54DV. I want to upgrade to another Garmin. I was thinking of getting Echomap 7 or 9 inch side scan. 
I want a side scan unit that is comparable with live scope. I’ve seen livescope first hand fishing with guides, it’s so friggin cool. 
The 7 inch is cheaper than the 9 inch. 

Is it worth getting a live scope on a kayak without spot lock.  I want to keep it portable  to keep it safe when not fishing. If  I do fish on a boat I could bring it out with me too.  
 

But I want to start with the unit first with side scan. Then get the live scope later if I want to.  
 

or is 360 better. I’m new to electronics  never had the money or a decent water craft until now. 

360 will mean you need to go humminbird. And humminbird has better sidescan. But... humminbirds livescope is gen1-class tech. 

 

On 7" vs 9" - I think you are kinda limited on what you can do with the 7"; they probably won't run a scope. And a little small for sidescan... fine for seeing rocks/trees/brush but tough to see a fish. 

Probably an ocean of livescope-ready garmin 9" out there from people starting with a 9 echomap on livescope and upgrading in a big boat, if you are OK with used. 

 

Sales are coming too, so there's that. 

 

Hopefully someone that's spent a bunch of time messing with electronics on a PDL will have some specific experience for you. 

 

 

Lowrance offers a package called the Eagle Eye 9. It is a 9 inch screen and transducer in a bundle for 1000 bucks. The graph also has basic sonar, GPS mapping, side scan, and active imaging (the Lowrance version of livescope).