Forget the rebuild/paint scenario. Labor charges will eat you alive, LBS are like
car dealerships, they have to be to survive. You will be much better off to
buy a new bike. $500-800 road bikes will be 2-3# lighter, be new!!, and fully
upto date. Paint quality will be vastly higher. Spray can paint is ok, but very
thin and builds slowly, scratches easily because it is soft and would be short lived.
You would need 2-3cans, at $5/can minimum. If your bike is freewheel (5-6spd)
then it would be even less useful to upgrade. 7spd might be upgradable to 8-9
spd but it would depend. Costs depend on the size of the project. Painting by
anyone other than you, would increase cost by 30-50%. Get a new bike.
Steve