Looks a little tight but I think it will fit. PCIe graphics cards are usually flush on the top where the RAM slots are and stick down to cover up some of the other slots. That way the RAM fits and the card fits. Yes, either one of those will fit. Another question is your PSU powerful enough to support those cards? It says 300W. It may work, I found this page about total system power usage for those cards:
http://www.anandtech.com/show/5541/amd-radeon-hd-7750-radeon-hd-7770-ghz-edition-review/23