I didnt go with the 965 because the 965 is much pickier with RAM timings. Also there is pretty much no gain in power or anything from using the 965 compared to the 945.
As for what processor, it supports Socket M. So it supports all T2xxx series chips (Core Duo/Solo), as well as Socket M T5xxx and Socket M T7xxxx (Core 2 Duo)
It does not support Socket P, which is what the newer Core 2 Duo chips are. So the question "will a T5500 work" is not answerable. You need to determine if you have a Socket M or a Socket P. This is useful:
http://en.wikipedia.org/wiki/List_of...icroprocessors
looking at it though, the 7300 is new, and therefore a socket P, and therefore
not compatible...