Fan should go towards the interior of the case unless your case has a vent below the PSU designed for it to be mounted fan down. The HAF does have a vent designed for that. Personally i would mount it with the fan facing upward to assist in exhausting air from the case.
The fatal1ty series isnt great but its not crap either, just dont load it up to its limit like its a high quality unit and you will be fine.
If you are running crossfire 600w+ is recommended but according to http://forums.overclockers.co.uk/showthread.php?p=16043... you'll be fine with the one you have. Best brands are Antec and Corsair, I haven't heard either good or bad from OCZ tho.
I have no idea about proper mount of the PSU
Edit: Plan on running Crossfire HD5770s and probably amd x3 or x4, not sure.
Look at the effective clearance below the case where the PSU fan is. If it's clear and nice then mount if down facing. If there is a remote chance that it will be blocked, mount the fan up facing (and be prepared for more dust due to the extra negative pressure ).