Running 3x Dell 2711's @ full res - HD 5870??

Hi everyone..
I'm new here and to the whole world of graphics cards... so hope you can help.

I recently purchased a new Dell XPS 8100 (w7,8gb,2x1tb etc)which came with the GTX260 1.8Gb Card which seemed pretty good.
I also purchased a dell 2711 monitor.

I now want to add another 2 2711's but the 260 only supports 2 outputs. Someone recommended the new ATI HD 5870 (2Gb) which seems to allow 3 with dualink.

I want to run all 3 at full res 2550x1440 (from mem). I am mainly doing graphics, editing and similar, but am also keen to get into gaming.

Can anyone shed some light on if this card will handle 3 diaplays at that res and also if you think this is the best card to go with or are there any other or better options?

Thanks for your time and answers in advance.

Chris