My experience with part time jobs is they use it as bait to lure you in and see if you're as good as the person recommending you says you are. If you think about it, it works out for them since they can see how good you really are on the cheap (relatively speaking).

You'll probably work part time ~1-3 months until they really start to pressure you to go full time (assuming they like you). This is NOT fun.

At that point you need to decide to go full time or peace out. They are not sustainable, especially when you are part of a team and the rest of the team is working full time, and they're getting all frustrated that so and so is out today because he's part time.

I would just save up and then work full time on your idea(s). Figure out your monthly expenses, figure out how many months you can go, etc. There's nothing more focusing than knowing you're losing $x a day out of your savings account by just not working - the Cortez approach, I suppose.

Caveat: This is, of course, my experience. Take it with a grain of salt.