I have my OSX86 running fine and dandy with a Q9450@3.0ghz on asus rampage formula.
My problem is i have a Radeon 4870 as a graphics card and a 620W power supply.

I'm considering grabbing a compatible geforce card and slotting it into my mobo along side the radeon. (what will happen? o-o)

I am also considering plugging in the supremeFXII sound card that came with my mobo, as my auzen prelude x-fi can not be used in OSX.

I'm anticipating horrible power problems and not making it past POST also im unsure how OSX will take the presence of a second GPU and a second sound card.

any suggestions or thoughts on my bad idea?

Well theres no support atm for 4870, not sure tho, netkas was playing with those in 10.5.7, check his blog for more info, if you wanna try another Video Card, check the HCL or post it here to tell if it gonna work, 9800GTX should work, now about the Audio did you check if there support for OSX? there some creative ones with full support... Hope it Help