I have picked up two Amiga 500s in ebay auctions and am going after a A2000 too. I want to upgrade their OS roms. Now here's the rub. I want to match as close as possible the hardware capabilities of these computers with the various OS's.
No such thing unless you mean NOT running AmigaOS 3.9 on a A500 with 1MB!
You can use 3.1 even on a stock A500, actually it is recommended over even 2.x as it is more compatible with older software.
But if you really do want to run the most software for the early machines I would get Kickstart 1.3 for the A500. For the A2000 2.x or 3.x would be the best bet as these OS's utilize a Hard Disc better.
Are the two main chip sets ECS and AGA pin compatible? Or is there an adapter possible?
No they are completey different and no adaptors are available. You will have to upgrade to an AGA Amiga if you want AGA.
What are the limitations of puttng a OS rom v 2.05/3.1 on a ECS chipset?
There is no limitation other than number of colors on a screenmode. (When comparing an AGA Amiga running 3.x)
Actually OS 2.x was created for ECS Amigas! As an upgrade for A500/2000 and the Amiga 3000 and 600 were also ECS Amigas.
Also do any of the kickstart rom switchers still exist?
Yes they do, keep an eye out on eBay or other sources. Maybe some of the dealers might have some in stock? I got a MultiStart II from Software Slut a few years ago...
