Is the old PC still running? why not use it as a server for a while, in a bit all of your must have docs will end up on your new machine and you can put the rest in deep storage.

Do a clean install on your new PC. Then using the modem router for your Internet (usually u can hook up more than one box) u can create a home network with both computers.

64bit is like a six lane highway compared to a two lane road for 32bit. Might as well use it.