Any of them will work well, assuming your hardware will support Windows 7 at all.
They differ in features. Get the features you need.
One is as "fast" as another.
With 3 GB of RAM, there is no reason for you to get 64-bit.
Probably 90% of people, me included, don't need anything more than the Home Premium edition.
You should probably go to Microsoft and locate the "Windows 7 Upgrade Advisor" and see if it complains about your hardware.