Dual-GeForce 7900 Graphics Cards – “Strictly to Be Sold with Systems Only”
 

At least one distributor of computer componets in the UK has the GeForce 7900 GX2 graphics cards in stock, however, no one can buy such a board, as the item is “strictly to be sold with systems only”, which means that enthusiasts who assemble their computers themselves cannot create systems with four graphics chips and enjoy increased performance with quad SLI technology.

The term "PC enthusiasts" is a term used loosely; the degree of experience ranges from a few months to >10 years with so many functional areas or area of expertise. I am not surprised for the decision - SI only product.

hmm.
I am eager to see what (if any) benefit is extractable from these qaudsystems.