Never get two mid-range cards, never.
The X1950XT would be best, but I would recommend a 8800GTS since you can afford it.
Well i really cant stretch beyond my 130 buget. The 8800gts is great but i can get two 8800gt's for 130 which although not quite as powerful will give a dencent boost over the 8600gts and will cost on average £50 less.
Unfortauntly gaming just aint worth that much to me.
Id agree about the x1950xt but i dont know about not having dx10?