Sounds like a good project. The best advice I can give you is to look up a good book on this topic. I recommend Dynamics of Flight by Etkin and Reid.
Here is the link to the new version
There is a cheaper Dover version as well.
The chapter on longitudinal stability will work wonders!
You will benefit yourself much more by finding the answers on your own than by us listing them out for you.
If you get stuck, we'll be happy to discuss your problem.
As far as manufacturing, the difficulty depends on your material and technique. I would say that in general most airfoils are similar in complexity and difficulty. Some people find a flat bottom easier.