The cheapest complete road bikes are the pista, IRO, Fuji, and the Windsor. You can find the Fuji and the Windsor on Ebay or at bikesdirect.com, but i think bikedirect is out of both. The IRO i just got has a nice reversable stem that can be flipped so you aren't resting as much weight on your shoulders. Maybe you can make sure they don't cut the steere tube too low so you can have the stem higher. like Ken Cox said, changing the seat height can sometimes help too. Converting is good, but if you are really worried about your shoulder, it might be a little harder to find a right frame/stem/seat combo that you can adjust. I have the IRO and I'm thinking of trying the stem flipped to see if it'll be more comfortable for me.