yeah newegg or tigerdirect is where i buy my stuff from. i have also heard good things about microcenter, but not actually dealt with them. if you want to go through them id read up on it but it sounds like theyre alright.
If you need a B&M, look into a Fry's Electronics, if you have one near you. They have a wide selection and had most of the GTX 670/680 models when I was there last. But they charge sales tax, where Newegg does not.