DJ, judging by this and the other topic, I think you overestimate differences between editions of Vista.
You can see the comparison chart here,
http://www.microsoft.com/windows/window ... fault.aspx
The only benefit of Ultimate worth mentioning, is that it can work with two physical processors (not cores), but it's a very rare combination and is used only on expensive professional workstations.
Other than that, there is
no difference between Home Premium / Business / Ultimate in terms of gaming availability or performance. Drivers for devices are the same for any edition. Vista flavors vary only by the amount of software included. Most of that software you won't use anyway.