Advice for College Junior

Hi, I was wondering if someone could help out and answer a few questions that I had. I'm currently a junior at a well regarded university in Chicago, and I was hoping to break into trading upon my graduation.

I'll be the first to admit that I've made mistakes during my college career and have wound up with a subpar GPA (~3.25 going into fall recruiting season). However, I'm positive that I still have superb mental math skills. I have taken the Optiver 8 minute test and scored a 72/80 so I'll have an interview with them in the fall. I know that that test is not the most rigorous thing in the world, and I'm not trying to say that I'm some supergenious because of that score, but I'd like to show that I'm completely in over my head.

My background in school is an economics major with some CS classes thrown in, and I hope to supplement it in the fall with some more analytical courses. My summers have been spent in academic research. I also have one quarter's experience at a boutique consulting firm. This summer's still up in the air as to what I will be doing.

My first question is if there are any other firms that offer a quick numerical test in lieu of a formal application for the first step that anyone knew of.

Besides that, what are other ways to make myself more appealing to recruiters? I'm an avid poker player, and have read through Sklansky's The Theory of Poker and a few other books. I've also read Monkey Business, Liar's Poker, and When Genius Failed. Next on my list are Black Swan and A Random Walk Down Wall Street. I've also been reading The Big Picture, Dealbreaker, Zero Hedge, WSJ, FT, and SeekingAlpha on a regular basis. This summer, I'll probably crack open Hull as well and go through an Excel book (any recommendations?). Is there any point to taking the GRE or GMAT? I scored well on the SAT in high school, and I'm sure that with a summer's preparation, I could score well on the GRE also.

Thanks for reading this post. Am I just completely doomed by my GPA trying to get into a decent firm next fall?