Paul, i reccommend looking at a 6800GT or ultra or 2x6600gt at least really if you want to SLI at all, (i have an XFX 6800GT)
Leadtek aren't a good choice, as they dont fit in SLI in this board (custom cooler they use)
the XFX card that i have is pretty fine, only minor niggle is that the fan is quite loud (louder than all the other parts in my system i think)
and if you really need Vivo, i'm sure you can step to getting a USB 56k modem, or something like that and a PCI card
oh, and it's not really worth putting an audigy in unless you have an audigy4 or similar i'd say, as the karajan module seems to be ok.
WD raptors don't gain much from Raid, i'd much more reccommend 1xwd raptor for boot drive, and a big separate storage drive, but up to you
take a look
here
other than that my system is basically the same as yours, and i'm liking it quite a lot!
oh, and running bios 217 appears to be fine for me so i might not bother updating till theres something worth updating it for (218 doesnt appear to change much unless you're having that nvmm problem?).