Oil base lasts longer and is more durable, but make sure to shut the gas off if your water heater is inside the house. Water base is almost as good and dries way faster. They actually have the stuff that dries in like 4 hours, and it worked awesome in my home. Why don't you do it yourself and save a bunch of money? It is super simple, i did my house. Are you staining it as well, or just sealing it up? If you are just keeping it the color it is, then all you do is lightly sand it, then simply brush it on and when it dries, you will not see any streaks. How much are they going to charge you?
