OK,... some easy help here. Please

The "broken" graphics card on new systems 10.6.4, is on the performance to playback HD movs. right ?

I am buying 2 brand new Octos 2010, just released 6 Gb etc... they come with ATI original cards. So those are broken under 10.6.4. OK so far.

Options -
1. Downgrade the system, wicht need to be by cloning another system.
That will work OK ? Snow leopard 10.6.1 or so ?

2. I saw here the GTX 285 option, looks as a great card, and looks NVIDIA cards are not that bad at the moment. ( I am shame to put a older system than came with the computer ).
With NVIDIAS 285's, I need to upgrade the drivers ? looking at the web, I found a updated driver with a CUDA support... we need that ?

Any way... Thanks for that.

Regards

Gian Bortolotti