Yes, all these cards support massive resolutions, meaning that the card will drive a screen of that resolution.
Unfortunately, this doesn't translate to gaming at maximum res.
Running Windows at 1920 x 1200 is one thing, but running BF2 at 1920 x 1200 is another.
I use the Dell 2405 and run BF2 at 1920 x 1200 with 4xAA, 16xAF and SSTAA, and get 50+ FPS with 2x 7800GTX SLi @ 490 / 1300. There is not a single card solution on the market today which can do this.
If you're looking for a <£200 card to run the Dell 2405, you're going to either compromise on IQ or resolution, maybe both in some games.
IMHO if you don't already own the 2405, you'd be better off looking at a smaller monitor (e.g. 20") and using the extra cash to buy a better card.
Hav