Yeah, the GTX 750 or a Radeon R9 270 OC = The non X version.
You get by with a 500 watt powersupply with the Radeon card. The GTX 750 needs much less power though.
Anyway, get a card that have a big and silent cooler like Asus, Direct CU, Gigabyte, or MSI. Beware of the Nvidia and Radeon referece cards that have a tiny fan that sounds like a hair drier.