Graphics card choice

I'm stuck between a GTX780 or R9 290.My build is an I5 4670K 16gb of 1600mhz ram, 120Gb SSD for a boot drive and a 1tb WD green for storage. 

What is the price difference between the two? At least in the US, the 290 is quite a bit more expensive than the 780.

In the UK its only about £30 with the 290 being around £370 and 780 being around £400.

Depends, If you want to mine virtual currencies like BitCoin then I'd recommend the 290 for it's hash-rate, also you can unlock some 290's and turn them into 290X's. On the other hand, if you aren't going to mine virtual currencies and only really care about gaming then The 780 is definitely the way to go for it's superior power.

But do keep in mind that if you decide to get a 290 then try and go for a non-reference model as those things run hot!

I wont be mining any virtual currencies, so just gaming really and i dont think Id buy reference designs for either of the cards, especially from nvidia, considering my PC is red themed :P  

Get the 290. The 290 and 780 perform very closely and when there is a difference, the 290 is usually on top.