Yeah, color me stupid. I opened up the case and immediately saw what you were talking about. When I returned it, the salesdoofus tried to tell me I could "easily" put an inexpensive PCI-E 1x card in. I had already checked newegg and found that low-end PCI-E 1x cards were going for $100.
Since the Asus 9500GT 128-bit 512MB DDR3 is $65 (before $15 MIR), I have no compunctions whatsoever about popping two of those in and having my secondary monitors be running off an "overpowered" card. Though another salesdoofus today told me 1) Going from multiple-monitors to SLI doesn't require a reboot anymore and 2) Crossfire doesn't require identical cards. #1 made me happier about SLI, but #2 made me think that doing a hi/lo ATI setup might be worth it... except I don't trust the salesdoofuses anymore, and I don't know that I'd get much of a performance boost in Crossfire if I paired, say, a 4770 with a 4650.
tl;dr version:
Screw the manufacturer overstock/clearance; I'm building from scratch and probably going with the dual Asus 9500GT setup. Now I just have to figure out a low-cost Phenom II CPU/mobo combo that will let me run SLI.
And KarmaKiller, that's a good build--with a second version of that GPU & the money I've already shelled for the PSU, that would clock in @ ~$545. In
that other thread I've got a build spec'ed out @ $650 before rebates. Though I like to save money, that $100 difference seems to buy some substantial performance increases.