Hi,
you will get a cooling problem with your system. Where do you wan't to play a huge processor-cooler and how do you wan't to get enough air-flow through your A1000 case?
I have made an A1000 with a PIII 933MHz and cooling was the main problem (the A1000 sits just in front of you on the desktop, so noise is another problem).
See some pictures about my work here:
http://community.webshots.com/user/Amiga1000PowerNoster
