Yes 64-bit will work. I have Vista on a MacBook pro -- version immediately before the unibody. Since Win 7 is basically Vista SE, I suspect that it will not be a problem. Depending on how much you plan to use it, a simpler idea might be to use VirtualBox or Parallels so that you can run it from within OS X. I am in a pilot group at work to examine using a single hardware platform regardless of OS...so I actually have nothing but Vista Business on the laptop. Vista recognizes EFI so, I need Bootcamp for drivers only -- so Vista is markedly faster to boot than say XP on a Macbook.
But if you just want to play around with Win 7, I would recommend using a VM. Then you don't have to mess around with partitions or anything else.Virtualbox
is a free download as well.