The Eastwood product I linked to is a two part catalyzed polyurethane clear -- fundamentally the same as what the "pros" use (including the same warnings to use a proper respirator because of the isocyanates). It comes in a special two compartment can. You puncture a seal between the two compartments when ready to spray and mix the paint and hardener. I've used the high-gloss version from another vendor and the results are fantastic. It's been on my commuter (which spends it's days locked to a bike rack outdoors) for 18 months and looks as good as the day I sprayed it (when I occasionally wash off the layer of grime). Of course with any paint job, the results are heavily dependent on the prep. But with some skill and patience, you can get amazing results from a rattle-can repaint.