The 6870 still destroys the 7770, however the 7770 is cheaper and uses less power.
See:
AnandTech - Bench - GPU12
I agree with the motherboard, for the SSD Dark Scyth could go for the 60gb and save a bit of money. Really depends on how many apps you want to install, then for the rest its personal preference, like you have found slower ram, slower processor and the build ends up more expensive. However you do gain a 90gb SSD which would be a great boost to any machine and overall it would still be a great PC.