If it were me.....

I'd get an entry level hybrid bike from an honest to goodness bike store. First, establish a good rapport with a bike store you trust. Second, if you are like many people, your goals in cycling may change with time. If you buy a good entry level hybrid, and if you decide after riding it for a while that you want to get into track racing, ultra-distance riding, or enter the weird world of recumbent bikes, you should be able to sell the hybrid with minimal loss.