I think you should visit also the Project Development Board as well someone might help your problem there. Anyway alt-coins is just almost a clone of bitcoin but customized to add some new features. That's all i know though!
You're right, a lot of the coins I looked at were clones of Bitcoin/Litecoin. But there's also altcoins that have developed their own code. I'm wondering if there are any more simple coins that would be a good place to start development practice.