So, if I understood correctly, you have Desktop (DT)
The only best option in this case is Sapphire 7750 low profile http://www.newegg.com/Product/Product.aspx?Item=N82E16814202002
Don't worry about power supply requirement, go to newegg feedback section, go to page 2 and look for TazarZero
post, read it.
Anything else I can help you with?