Which GPU for LCD?

[SFFNoob]

I'm in need of your wisdom fellow members!

I'm finally getting my HTPC together and was wondering would a HD4850 with 512/1024Mb be sufficient to play games on a Samsung 1080p screen? Or should I look at a HD4870 with 512Mb as I've been told that would be better at 1920x1080 over the HD4850 1Gb!

Any idea on what these parts go for used nowadays as I'm not looking to buy new ATM?

Unfortunately, I've seen that access to the members market is locked to users with >250 posts and 3 months usage of the forum? So that counts me out but I wanted to ask as I'd be looking elsewhere (friends and other forums, sorry, I love the OcUK forums!).

Thanks, all pointers would be welcomed!

 

[SFFNoob]

Thanks folks for your replies.

I'd be happy if I can get it to match that of the PS3 and XBox360, is it possible? I have no idea on PC gaming, it's family requests!

 

[SFFNoob]

Again, many thanks to everyone!