a dual boot was something I was looking at and advised against because it wouldnt run as fast and you are doubling the amount of problems you create for yourself as they can conflict and also if one messes up chances are its going to take the other one with it.

personally I'd just run a 64 bit and leave it at that or get two hard drives and run a dual boot that way so you can pull the power cable out the drive you use only seldomly. I built my PC from scratch and installed Vista all on my own and running sweet as