Well yes, but I said that because it sounds like you have dropped a good amount coin and TIME into making this bike look and feel how you want it. Personalizing is a significant effort. Its never nice to do all that work just to just blow it out. If all else works well and its pretty much been rebuilt, your going to have a hard time finding another one as nice as yours. And not just that, after doing all that work its nice to know the "latest" history on the bike.
I THINK you share the same motor down to maybe like a 97'. I have ran across three complete motors on craiglslist in the last couple of months between $100-$250, long blocks. Keep an eye out on Ebay as well. You might be able just to swap in the tranny.
I know you can "patch" where the 5spd misses with gearing ect, but the 6spd is really nice. It's consistently on the pipe.
The needle WAM talks about sounds nice. I am thinking about going with JD's kit. It's suppose to be really nice. The trick with there kits are the needles as well.
I did the PV governor stiffer spring mod just two weeks ago. And YES, took the initial bog when cracking the throttle out! A must do.
All these mods mentioned will def help your drop in RPM in the shifts. Dial all these in, and keep an eagle eye out for the 6spd. You will not be throwing your money away by doing the needle, spring, sprocket ect on the 5spd... So if you ever do drop in the 6spd, it will only make things that much better.
I also plan on doing a 134 or 144 EG build.