I've got several A2000. Unfortunately, they are pretty useless without some turbo CPU card, because 68k is too slow for tcpip and most other important things. For eg. I have Picasso II gfx card but can't run P96 drivers 'cause they need at least '020..
Even if you can find faster CPU card for A2000, it will probably cost much more than A2000 itself. The same applies to a1200 and most of other Amigas.
Your best chance is to get already accelerated Amiga for small price.
I do HOPE that coldfire will be usable on other Amigas besides A1200..
PS. IMHO CDROM is not essential if you network A2k with some other computer (nullmodem/parallel..). You can even use floppys like in (good) old days.