Ok, since this conversation is going down two paths...
Drew... Stage illusions are probably going to be too expensive to be a viable option. If I were you, I'd take what I already know, and see if I could adapt that to performing on stage.
For example, can you use jumbo cards for some of your tricks? Can you arrange for a camera perhaps to project a trick or two onto a big screen? Maybe throw in a mental card trick as well.
Since it sounds like you've mostly been studying card stuff, that's probably the best course of action. There will always be tricks as well that play just as easily to a big audience as a small - you just need to maintain visibility.
Regarding youth @ mentalism...
I recently had a discussion with Bob Cassidy on this very matter, actually... It depends. There was a topic on the Cafe along these lines as well. I think the basic general consensus was, it's probably easier to go with a psychic persona. You don't necessarily need as much knowledge to explain your persona, for example.
However, I'm personally reasonably young (I'm at Uni), and from my experience, being young does not preclude you from using a psychological persona either. Whilst I do not have nearly enough experience or knowledge to present myself as an expert in manipulating psychology and other such things, I do study psychology, have a genuine interest in it, and that's how I present my persona - as a student of psychology, exploring genuine psychological phenomena. I'm obviously biased, I might in fact be the worst mentalist in the world, but I think it works for me, and it's something certain people can pull off. In any case - it's definitely not a given that young people can't perform mentalism convincingly, or that young people can't use a psychological persona.
There are two other important factors that come to mind - age, and context. This works for me because I'm a uni student, and a psych major. Obviously, someone a bit younger wouldn't be able to pull off a student with requisite commitment. Also, I prefer to perform at intimate gatherings, and generally perform for friends, and through word of mouth; because of that, I obviously can't claim psychic powers to my friends, that would be ludicrous.