Well:
I don't intend on doing any live shading.
the gfx card not really about that. its just a about raw speed. You actually want to buy the best card you can afford by any stretch. No question about it. See theres nothing as valuable in the chain as you are. Your cost trumps everything else 10 to 1 see you need to be paid monthly about the cost fo a graphics cards in teh calculations.
2. Even though I know that 64 is better than 32 I really don't understand it
like what kind of increased performance will I see as a result of using 3ds64?
Well lets put it thisway, theres no added benefit from 32 bits. Theres nothing you have problems with in 64 bit land really, theres used to be but thats years ago. The only thing that MIGHT be a problem is that if your a corporate user an ahve applications that absolutely need internet expolorer 6. But hey your order for those software was a mistake you now pay on.
64 bitness is also easy to explain. See 32 bits can only point to 3 gigabytes of memory, tough in reality 1.5 per program, and 3 in extraordinary circumstances. Now 3 gigs is not much when it comes to 3d. We passed the point where 32 would be anough somewhere around 2002 permanantly.
Both of theese translate to same thing:
more geometry/stuff on screen without crashing your computer. No other benefit really. But this is a HUGE benefit. Because it saves you time optimizing things out. That said if you dont buy atleast 8 gigs of memory your screwed anyway, and that is not possible 32 bit land, can not be done.
So if you really want to fail in the future sure go 32 bit. You just can not compete against people with 64 bit on most jobs they will run around you in corcles when it comes to complexity and render sizes and raytracing speed. When you economize they pump more.