Mining Litecoin with GPUS is not going to be profitable, as there are scrypt asics out now that will push the diff sky-high. See for yourself using a scrypt profit calculater, for instance:
coinwarz.com As it stands now, the electricity will cost more than the profits you are hoping top make.
I would suggest that you look into alternative algorithms like X11, X13, X15. Read up on what crypto currencies you find good and join a mining pool. If you do not want payouts in a special currency other than BTC, then pointing your rig towards a multipool is probably the better option for you.
As an alternative/comparison, check
my sig and look at hashlets. You could get about 1.2 MHps with your two cards. 1 MHps of scrypt cloud hashing starts at $15, but I would go for the Zenhashlet that is $21.
If you still want to use your cards for scrypt mining, look here for a few cgminer hints:
Litecoin.info
