What size shimano Sahara FE series will best fit my st croix premeir 6'6 med fast spinning rod

2500

2500

x2

x3

I had an older Sahara for a few years.  I unfortunately killed it when hooked into a monsterous catfish.  The new one is far improved and one of the best bangs for the buck.  The 2500 size is fine for bass fishing.  Pflueger Purist would also be a nice option in that price range.  

Definitely a 2500. No need to go bigger in my opinion.

You might want to check Dick's for clearance specials.  I picked up a Sahara 2500 (FD) a couple of days ago for $35.  They also had a 3000 FD for the same price.

Be sure to try a new Sahara on a rod first - wind and make sure the bail does not hit your fingers ... On the previous version Sahara 2500 I had to give it to my son for that very reason as I found the reel sits too close to the rod for my tastes as compared to Daiwa or Abu Garcia .