I you are solo mining you need to solve a block and hope for the 50 LTC reward and the odds are kind of low so you are better with a litecoin pool.
Look at this calculator, you will see:
https://www.litecoinpool.org/calcI do use cudaminer with coinotron, stratum and mining_proxy.exe and it is working ok.
Here's my setting for mining_proxy.exe :
C:\minerd\mining_proxy.exe -pa scrypt -o coinotron.com -p 3334
And here's for cudaminer with 470 GTX, you should change 28x8 by "auto" to help find yout best config
cudaminer.exe -d 0 -i 0 -l 28x8 -C 0 -m 1 -o
http://localhost:8332 -O elessdai.1:x
Hope this help