Downclock the crap out of it and make it a HTPC. That's what I'd do anyway.
This isn't a bad idea and you can use the second 9800GT for dedicated folding if you choose to leave the system as it is.
If the hardware was directly traded off for hardware more suitable for an HTPC this is something that could probably be accepted but if you do this try to keep as much of the original hardware as you can. If you trade off the 680i board and a single 9800GT you can get a more reliable and better suited motherboard like a Gigabyte, ASUS or DFI P35 board. Personally I would see no wrong in this and I don't think many if any would disagree that this would be acceptable to keep the bulk of the machine or as much as you can intact and only changing out the parts that would make it better quited for HTPC use.
If the system did not have a PSU, HDD or optical drives then it could be considered acceptable to trade off the board, CPU and one of the video cards for a lesser, dual-core CPU, decent yet reasonable board and a PSU and HDD as this would help keep the value of parts traded about equal while making the machine fully functional and as long as you keep the ram, case and one of the video cards then all should be well.
Edited by WARDOZERX, 12 April 2012 - 04:59 PM.