You are on the right track, but Im about your size and need a 56c. The bike in the pic looks no bigger than a 52. Might even be a fitty

Just for the purposes of encouragement, I buy these kinds of bikes from CL all the time. A totally bombproof commuter that will need nothing but a shot of WD-40 occasionally can be built for 300.00 if you take time to find the right starting project. Happy hunting!!
My general rule of . . .
whatever 
125.00 for bike
100.00 for tires
70.00 for lights and mirrors.
5.00 for can of WD40