Matt,
First off great plan to shed some weight, I weighed 260 last year now I'm down to 190 and I love life so much more I'm thankful for my changes. I didn't start biking until this year, so I didn't have to buy bike clothing when I was heavier, my suggestions however would be to go with maybe a mtb short or a normal bike short and wear a pair of basketball shorts over them it's what I did when I started riding becuase I wasn't going to be one of thoughs weirdo's wearing spandex all around town, I think I even told my family I'd kick my own @$$ if I wore just spandex. But after awhile it just happend and now to me it's normal to walk around with the world to see my bulge, the neighbors still look at me weird but oh well. Anyway that's my advice normal bike shorts with basketball shorts over them, and they make a coolmax kinda t-shirt but I'm not sure on this one I perfer to wear the most out there jerseys avaible.