To try to answer your specific question, re-gel-coating is normally regarded as a total pain in the rear, and so not worth doing. Huge amounts of work to grind all the old stuff off, then you have to get the new stuff to set which means adding the right amount of wax (it normally only sets when air is excluded, which it is in production since the gelcoat is the first layer applied to a mold, with fibreglass applied ontop), then it's hard to get a decent finish: you'll never get a smooth finish when first applied so you'd probably have to sand it all down then gradually polish up all over.

It's generally reckoned to be much better to do as others have said and paint it.

cheers,

dave