|2) I already have xp pro sp3 32 bit. Can XP Pro work well with the I7 machine, or will it merely 'work', but not utilize to the fullest extent the multiple cores?|
Here's what I wrote yesterday for a guy wanting to use XP on a Core i3:
"Win7 is quite a bit better than XP at managing multi-core and especially virtual CPUs. This is particularly important for Core i3 and i5 6xx CPUs, as they heavily depend on hyper-threading to deliver near quad-core performance."
Of course, the i7 CPUs also feature HT but from what I've seen, the quad-core i7s do not benefit as much from HT as the dual-core i3 and i5 6xx processors. This may change in the future.
XP will work and it will even see all 8 logical cores, but Win7 will do a better job keeping them busy. It's just a better threaded OS.
3) I also have Windows 7 Ultimate 32 bit. Similar question as (2): Will this work well with the I7 machine, or will it merely 'work', but not take full advantage of the multi cores of the I7?
The only thing Win7 x86 won't take full advantage of is your 4GB of RAM. You should definitely use an x64 edition, since you plan to "expand to 6 or 8 in the future".
4) What are the differences between the editions of Win7
(home premium 32 64, Pro 32 64, and ultimate 32 64)?
The Home Premium x64 OEM disc is what most home PC builders look for these days.
Super 939 | Dual-core Opteron 185 @ 3.2GHz | 4GB PC3200, CL2 | 1.0TB
2x GeForce 8800GTS in SLI | Blu-Ray | X-Fi Ti Pro PCI-E | W7 Ultimate x64