Doubling up the 8800 GTX - Yay or nay?

Hi,

I'm looking to give my machine a bit of extra bite without actually having to replace anything, looks like the 8800 GTX is pretty cheap at the minute so I was wondering if it was worth getting a second one and SLI'ing them. I've read the FAQ stickied on this board and there don't seem to be any glaring negatives.

My main worries are:

Power - I looked at the power guide and my BFG supply was NOT on there... even though its 800watt. Even if this is okay I've had so many problems with cable lengths and number of plugs, I'm worried I'll get the second card and won't have the connectors to actually fit the damn thing.

Space - My case is... big... but there still doesn't seem to be any bloody space in there, pokey little holes for sticking cables through means its pretty tight and I assume you wont the cards in the top two PCI-E slots... which leads me on to my third worry..

Heat - If i got another of those cards AND managed to squeeze it in they would be next to know room between them, surely it'l overheat and die on me....


Any advice and information is MUCH appreciated.


My System:

Intel Core 2 DUO E6600 "LGA775 Conroe" @ 2.70GHz
BFG nForce 680 (Socket 775) PCI-Express DDR2 Motherboard
BFG 800W UK/PFC Approved PSU
BFG GeForce 8800 GTX OC2 768MB GDDR3 HDTV/Dual DVI (PCI-Express)
GeIL 2GB (2x1GB) PC6400C4 800MHz Ultra Low Latency DDR2 Dual Channel Kit
Samsung SH-183LBEBN 18x18 DVD±RW Dual Layer Serial ATA Lightscribe ReWriter
Antec P180 Advanced Super Midi Tower Case
Seagate Barracuda 7200.10 320GB ST3320620AS SATA-II 16MB Cache
Creative X-Fi Xtreme Gamer 7.1 Soundcard

That psu has 4x6pin pcie connections
64a

more then enough, Im using a 750w 60a silverstone psu with 88gtx oc sli, been almost 2 years now, no problems with 3.7ghz cpu