I agonized over which boat to get, demo'd, and finally boat a Jackson SuperStar on an impulse because the colors were sweet. After a season in it and lots of time at playparks, I think that while the boat is great, and definitely the most popular on the river, that the differences are pretty subtle. I've got friends in biscuits, projects, even seen some BlissSticks. We are all basically able to do the same moves nearly equally as well. So I'd get the cheapest one you can find.
The main thing is going to be getting a boat the right size for you. A star, biscuit 45, or project 45. If you are dying for comparo: the biscuit is probably looser and loopier, the Jackson good all around but better for cartwheeling moves than the biscuit. Projects seem to struggle with loops, but that could be just my perception.
One more thing, make sure you get your body into the correct position in the boat. Fore/aft body position really helps with everything and at your low weight for your height be sure you can get forward enough to balance. Might make a good deciding factor.