Are you limited to Novatech? This is good value, imo:-
Heavily overclocked 7900 GS for £70.
Btw, if you're serious about DX10, I would wait a few weeks for the 8800 GT to appear. The 8600GT and X2600 XT are next to useless for DX10 shader games.
The X1950 Pro does have a 6 pin PCIe type connector. Your PSU should be able to accomodate this, though, unless it's old (in which case it might not be up to the job of powering that card anyway!). The X1950 Pro I briefly owned (3 days) did come with an adaptor, though, which allowed you to use two molex connectors instead of the 6 pin connector.