Hello. Your case can have up to 300 mm card. ASUS 670 is 271 mm, so the answer is yes, it will fit.
660 ti is even smaller than 670 so it will fit too.
You should consider of getting 760 instead of both of those card. 670 and 760 perform almost the same but is cheaper. Here is benchmarks - http://www.anandtech.com/bench/product/830?vs=854