I have an EVGA GTX 750Ti. It's a small, dual slot, single fan gpu and should fit almost any case on the market. The ASUS cards are mostly dual fans and may not fit all cases.
The dual fan ASUS cards are about 8.5 to 9 inches and the Shinobi looks to be able to accomodate cards up to 12+ inches. You should be fine with an ASUS card.