Getting started in Chicago

Hi, I apologize for the newbie question. I'm new to swimming (kind of) but wanted to get started doing open water swimming once the weather in Chicago starts to behave. I'm currently swimming 2000-2500 pool yards 2-3x a week (in addition to running 20 miles a week.) I did sign up for the Big Shoulders 5k outdoor swim mid September as a outdoor goal. I'm not swimming for time - I'm swimming just to compete and finish. So a few questions: 1) Suggestions on wetsuits? I don't want to say "money is no object" but I'd rather pay to do it right the first time. 2) Did I bite off more than I can chew? I can do little over 1000 yards without stopping but 5 months to 5k - bad idea? 3) Any other advice?