3 slots-- 2 in SLI 1 not

I plan on using two 9800GTs (as they are the most powerful cards that I can find that take up only one PCI slot**) and a 9800GTX+ (what I currently have, it takes up two spaces). The math works out well as far as there being a benefit to SLI'ing them.
But my question is, on a
EVGA E758-TR 3-Way SLI (x16/x16/x8) LGA 1366 Intel X58 ATX Intel Motherboard
http://www.newegg.com/Product/Prod [...] 6813188046
Am I able to SLI the two cards in the x16 slots and leave the 8x slot un affected so that I can use it to display the other two monitors I have on my desk? I currently am using two video cards that are in no way connected (other than being on the same board, no SLI bridge and no BIOS pairing).
The end result is three spanned monitors. This will be in Vista 64 bit, and will be on the i7 CPU (apparently that makes a difference with SLI?)
**Please do not suggest alternate cards, unless they will take up only one slot. I have to plug in a RAID card (PCI express x1) and an audio card (PCI).

End result:
EVGA E758-TR 3-Way SLI (x16/x16/x8) LGA 1366 Intel X58 ATX Intel Motherboard
2x 9800 GT
1x 9800GTX+
i7 920 2.66 GHz
1200 watt PSU (just putting this here so that nobody says “you need a big power supply! Blah, blah, blah!”)

Not to doubt you (especially because you are giving me the response I want ), but is there any documentation you can show me? something maybe from the nvidia site?