Considering an upgrade...

Alright, so I've had my 9600GT for about 8 months now, and it's done pretty well so far but I've finally realized it's time to upgrade. I recently bought Empire Total War and that's when I realized that the 9600GT wasn't the best card to play said game at 1650x1080 with max settings, so I was thinking about getting a 260GTX (I have a budget of about $250). Before I upgrade, though, I need to make sure that that card would be able to fit in my computer case. I have a stock gateway mid-tower case which does an alright job of squeezing in the 9600GT, so should I upgrade my case before I even consider upgrading my graphics card? Also, since the 9600GT only takes up one PCI express slot and its looks like the 260 takes up two, would that fit as well? Would pictures of the back of my case help?

tl;dr - will a 260gtx fit in a stock gateway mid-tower case?