[Finster]

It really depends on how brave or what your comfortable with. Two part poly is an out standing long lasting finish but can be very harmful. Single part poly is more user friendly not as long lasting. Gelcoat is user friendly, cost effective, and has an easily repairable finish, though labor entensive to apply and maintain.
Though you can "role and tip" a two part poly safely as FS mentioned, I've never done it but I hear it's hit r miss.

You should contact Ebeach, he's the gelcoat master.