Can't comment on all ( actually not on most ) but I do have a few comments / thoughts since I've just been GPU shopping and use "big" screens.
Depending on what type of games you play and the monitor you buy ( does it support 2560x1600 - the one u posted doesn't ) i.e u'd run 1920x1200 then ya GPU might be overkill for current scenarios.
If you look at that one u'd see what the 9790 pulls in framerates at max settings and 16 AA - if you look at the other games u'd see u in most if not all cases can go w something cheaper/smaller.
Personally I ended up w a Gigabyte Nvidia 660 OC because the OC ed has 2 fans and very good noise vs temp and pretty good performance - Gigabyte also has ATI ed's w that look for Windforce mark on their website ( the ti ed is there in the link but there's also a regular 660 reviewed somewhere on Anandtech ).
ATI or Nvidia? depends on prices in your country and what u feel fits your needs the best --- I go back and forth between them. ( and you can always SLI later on if performance becomes an issue...the GPU will be rather cheap then to pick up a 2nd ed of if the mobo can handle it...did not check! )
Personally I'd also go for a bigger monitor - I have a 27inch HP 2710 - 3 years old and out of stock...but personally I'd rather spend 100 euro less on a GPU ( than overkilling it ) and get more screenspace
Especially if you also need to do autocad, if you program or other cases where screen space is nice. ( unless you go dual monitor ).