I use a biostar A880G+ micro atx. It comes with 2 ram slots and hdmi port. I have the ram set at 1600 and use the p-states setting for underclocking my sempron. It will also overclock your cpu if you desire and unlock cores, though the success rate varies. I suggest with the money saved you get a better power supply. The HEC won't cut it in the long run. I like antec or ocz. IF you need more slots, a full atx version of the 880 is available.
The ASROCK 880GM-LE is probably good enough as an average motherboard. Im thinking youre putting too much thought into your motherboard and not enough into your graphics card. The most important thing about MOBOs is that they are upgradeable in the future. The ASROCK 880GM-LE only has 2 memory slots, i would suggest 4, for future upgrades. also i would recommend a board with 2 PCI-E x16 slots for future SLI/CROSSFIRE upgrades, and trust me, with the 5770 youll need crossfire to play new games on decent settings. I have has the 5770 and did not like it much but it played crysis for me on max settings but NO antialiasing.
I should also mention something about having two PCIex16 slots for crossfire; make sure they are spaced far enough to utilize Crossfire. sometimes they are right next to each other and youll never be able to crossfire with larger cards. the mobo above is enough space however.