Card to drive Dell 3007WFP 30-inch LCD monitor

Hi,

Disclaimer: I've been a Matrox Parhelia user up to now so please excuse
my ignorance of cutting-edge nVidia technologies!

I'm planning to buy a Dell 3007WFP 30-inch LCD monitor, which runs at
2560x1600 (same res as the Apple 30" Cinema Display), and needs to be
driven by a dual-link DVI connection.

Dell have apparently worked with nVidia to provide some extra controls
for this monitor in their graphics driver, so coupled with Matrox's
apparent inability to produce a DX9-compliant card after all this time
I'm almost certainly going to make the switch to nVidia to drive the
new monitor.

The question is, which card should I get? From what I've read on the
web so far, the XFX nVidia GeForce 7800 GTX cards look to give the best
power-to-cost ratio, so I was thinking of going for one of these - does
anyone have any opinion of these, or does anyone know that these will
definitely work with the Dell monitor? Alternatively, does anyone have
any alternative recommendations for my situation?

(If you need to know anything else to answer properly, just ask!)

Thanks very much for any help anyone can offer.

Duh, one thing I forgot to do was ask about the XFX card's TV-out
capabilities. Can anyone confirm that this card will be able to output
to S-video while I'm using my dual-link DVI monitor with it? For
instance, so I could play a DVD back and have it full-screen on my TV
via S-video, while working on my normal computer screen?

Currently my Matrox card automatically plays back anything that's
playing as an overlay on the main screen simultaneously on the TV
screen, with full overscan so that it looks exactly as if I were
watching it on TV normally - is this achievable with the XFX GeForce
7800 GTX card too?

(Sorry if these are completely stupid questions but there seems quite a
high level of assumed knowledge in most of the info I've seen about the
latest nVidia cards - perhaps because they assume that anyone buying
such cutting-edge products already knows what they can be expected to
do!)

Thanks again everyone!