Sorry but your argument is fundamentally flawed. Primarily because W7 is a modular OS and therefore is far superior to Vista for a start, and secondly because of the memory addressing issue - a 32bit (x86) OS can address 32^32 memory modules whereas a 64bit (x64) OS can address exponentially more, ie 64^64 memory modules. This equates in the final analysis to a 32bit OS seeing a MAX os 3.47Gb of RAM but a 64 bit OS can see up to 128Gb RAM.

64bit is certainly the way forward....

I would try to reflash using the VM inside W7, and failing that run a dual booting machine with an old XP or Linux install as the alternative OS for flashing only.