Even if you don't like the intel based build, please do not go for AMD APU because in a few months they will launch Trinity APU which will not fit into these motherboards incase you decide to upgrade. So if you intend to go the AMD wat look for Am3/AM3+ based motherboards and CPUs. Here an alte AMD based build, with the CPU, motherboard swapped for AMD, at the same price. Have a look:
CPU & CPU Cooler: $115- AMD Phenom X4 955 OEM & CM Gemini(CPu has $10 off with promo, also 3rd party cooler needed becaue the OEM cpu does not come with one)
Motherboard: $45- Biostar 780G
ODD: $17- Asus or Samsung
This computer most likely wont be seeing any upgrades. at most just a graphics card upgrade. the only games this pc will see are the sims 3 series and older games
so do i really need that 7770?
Yes you can downgrade, to a 6670. but 7770 is more powerful(and costly). But in case you decide to get a new monitor , or say connect to a TV , and say play games there. the 6670 might not be able to cope up. Also this GPU gives option play play most games without any problems.