Windows 7 Professional x64 is the one to go for. Unless you have a 32 bit only processor (which apparently you have determined is not the case), there is not much point in using 32 bit versions of Windows anymore.
Regarding the upgrade version question... MSDN and MSDNAA copies of Microsoft software are typically retail licenses, unless otherwise specified. I didn't see anything indicating that they were not retail, so it shouldn't be an issue.
ok but theres an x86 copy isn't that also a 64 bit copy?