Secondly, what is the deal with accelerators and ram expansion these days?I have been looking at the ACA 1232 Accelerator with 128MB RAM from amiga kit, is this the way to go?
I guess it would be ok for retro gaming and small tinkering. For an other option I'd look for used Blizzard cards (B1230, B1260...).
Thinking Amiga OS 3.5 might be nice?
I don't see any point in OS3.5. Either choose OS3.9 or stick with OS3.1. 3.1 is more slick with 030 and can be expanded pretty much to the same level with 3.5/3.9 with 3rd party software.