First, you really want to quote or at least link to the entire spec
The difference between 32-bit and 64-bit is that 32-bit only supports up to 4GB of RAM.
You'll have 4GB RAM, so 32-bit is sufficient.
As for the version (Home, Pro, Ultimate), take a look at this baby.
Home Premium should be good enough for most people - unless you really need the extra features of Professional for £30 more.