I would not worry about accelerators unless you are into making a hot rod. I like the idea of keeping the hardware as it was in 1980s, bigger hard drive not withstanding. There is a ton of cool system 6 software to keep you busy. You can also hook them to the Internet via a raspberry Pi, that is allot of fun.

Interesting that you got your fan to quiet down. One of my SEs has a hamster wheel fan type and it is laud as heck. I have been thinking of replacing it but It currently in a fairly original state and I don't want to disturb that.