I'm not a pro on this, but you wont have any problems as long as you don't overload youre CPU. The only difference with a 64 bit version, is that in theory you can do 64 commands(bits) at the same time(paralel) and only 32 commands in the 32 bit. Youre system have the opportunity to use 64 bits but will only use 32 bits. Please correct me if I'm wrong. So I don't think you'll get any problems unless you're really pushing youre systm.
This is taken out from my microcontroller/microprocessor knowledge, so the main thougts are the same.