I'm in about the same boat. I still have the same old A1200 however, so I just had to dust it off.
I'm using an 040 in a stock 1200 case, but I added a small fan venting out the rear of the case. It keeps the CPU card cool enough to run without any problems.
I still use Final Writer 97, and it seems to run fine on this machine (OS 3.9).
Good luck.....
