Graphics cards
 

I've asked this question on the Grass-valley forum but without much success.

I'm looking to build a new PC machine and need advice on a graphics card. I'll be using Edius Broadcast 4 and will mainly editing HDV footage from a sony Z1 and Canon XL H1. I'll be producing HD output to external hard disk for delivery.

Can't afford the top FX cards. Overwhelmed by the number of options out there. NVidia or ATX? etc. What card is the best bet for a decent system?