Z77 Boards; Pro4 vs TZ77XE3 for 2560x1440

So I'm slowly finishing up my build. Unfortunately, it includes a 2560x1440 monitor, so I'm torn between 2 different paths;

1. ASRock Pro4 ($150) with 1 good GPU (2GB+), not sure yet. Save some money on a PSU, get a 650W maybe, save some money on electricity over the long-run (lol?!)

2. BIOSTAR TZ77XE3 ($140) - surprisingly cheaper, even though it has 2x pci-e 3.0. Then get an SLI solution, 850W PSU.

Ideas/suggestions which path to go?

Also, why is the ASRock Extreme4 so expensive ($180) compared to Biostar's at $140, I see almost identical features. If anything, I might as well get the $140 biostar, then have the option to go SLI down the road (unlikely though).