I use Cryptsy.com for all my non-BTC transactions. It has markets for pretty much every coin out there.
For you, I would do Middlecoins. (
http://middlecoin2.s3-website-us-west-2.amazonaws.com/)
It essentially mines the most profitable scrypt coins, based on the price at the time, and converts them to BTC for you automatically. The fee is fairly high, at 3-4%, but likely worth not having the hassle of trading the coins and the fees involved in moving them around.
Right now, I am pretty sure it mostly mines Doge, but it varies from day to day. If you are looking just to mine a single coin, I would suggest Doge might be more profitable than LTC, but it depends on the prices.