The HD7770 is not a bad card, by any means, but, even at your resolution, would be limited in some games. You don't give any prices, so I don't know what, if any, spare you have in budget. If you have a little spare, something like a GTX 560, or a HD 6850 would give a better performance, worth a little additional cost (of course, depends what actual prices you can get).
Are you planning to overclock CPU? Don't forget aftermarket cooler, if you are.
Not familiar with Foxconn mobo (in UK), so can't comment on that.