Windows 7 Ultimate has far too many unnecessary add-ons which slow down processing therefore waste resources too.
What are you refering to exactly? I can think of a few things like 'add-ons', but those can easily be turned off, if they're not turned off by default, which I think is the case.
I'd go for Ultimate anytime, 32/64 bits choice is more important. If you lack RAM and overall computer power then you should choose 32 bits, because it requires less. The 32/64 bits choice is mainly a compatibility thing. I haven't had any compatibility problems with 64 bits yet, though.