Thanks for the suggestion but I am not sure If I should get a modular power supply or not for better cable management.
Well even if you want to spend double $ just for modular, at least take an 7850. With the amount of $$ you want to spend is ashame to stay only in 6870 (although is a good gpu, but 7850/7870 are better).
not bad, but as memnarchon said, you could save up a bit with the PSU, and use the cash you just saved up for a better card. a few dollars on cable ties may not be as good as a modular PSU for cable management, but it helps. though, correct me if i'm wrong, but i'm quite sure the EarthWatts series doesn't come with a power cable, so you should make sure of that if you're going to get it.
just noticed you're getting an H67 board. make sure with the site that the motherboard you're getting is updated with the latest BIOS, if not, BIOS P2.10 at least. otherwise, i don't think your 3450 would work with the board by default.