The seven-set is only in the 0.5 meter length, if I remember correctly, which is a great length for many cases but can be too short in other cases. If you have a source that will be close to the 950 and connected via analog cables, get that one. Otherwise, I'd probably get the three pairs and have one extra.

Cable pricing is an oft-discussed issue, and everyone feels differently about it. I think the PSC's (as well as the PCA's, PDO's, and PSSV's) offer more quality for less money than some other often-suggested brands - I replaced several BetterCables Silver Serpent s-video cables with PSSV's a year or so ago - but I always recommend that you get what you and your wallet feel most comfortable with. I've got a couple sets of BlueJeans Cables component cables in my system currently, because when I put them in that was what my budget was more agreeable with.