Matching Amiga Roms with motherboards rev

[Dropcheck]

Hi everyone,

   I have recently returned to the Amiga Scene after about 15 years and I find most of the memory I had stored in my head about Amiga has been erased.   :crazy:

   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.  

    Some questions:  

    Are the two main chip sets ECS and AGA pin compatible? Or is there an adapter possible? What chipset upgrades are available for the original ECS?

    What are the limitations of puttng a OS rom v 2.05/3.1 on a ECS chipset? Also do any of the kickstart rom switchers still exist?

Thanks
   

[Dropcheck]

Thanks TjLaZer!

     Think I've got partial memory return now.  Probably need to get a battery backedup static ram upgrade.  That's my next goal. :crazy: