However, the last time I tried 64 bit, admittedly quite a
while back, there wasn't much software available.

I've done some research via Google, and it looks like the two biggest
concerns are Flash and Java.


I never had much with 64-bit Linux until this past year. Everything works great.
I tried the 64-bit version of Ultimate Ubuntu 8.10 and then later Ubuntu 9.04
64-bit and both work great. Zero problems.