Clearcoat isnt a problem on gel coat if you use a clear gel coat and not automotive. It will give you the long term gloss you are looking for and prep is the key. Sand the suface some with 600 grit enough to try and take off any oxidation, then wipe with acetone. BE SURE you have good ventilation...!!
Duratec clear is a good choice and the only thing I use.
Your goal is a total of 4 to 5 medium wet coats because you want to have enough on there to sand and buff if need be.
By the time you finish your first coat the first part you sprayed first should have had enough time to flash. If not wait 10 to 15 minutes and be sure to work fast after you catalyse your clear. Depending on temp you may only have 10 to 20 min at most to spray and clean your gun (with acetone) or it will set up your gun and your done for the day.
After you finish you last coat wait 30 minutes and then spray the entire thing with p.v.a.(poly vinyl alcohol) to reduce tackiness in your final coat.
Wait 24 hours and then you can sand and buff any defects if you want to.
The p.v.a. washes off with soap and water...
Hope that helps. Its quite a pain to work with gel and pretty messy. be sure and have at least a gallon of acetone on hand and dont forget to catalyse your clear at about 2%
If you need any more info let me know if I can help and GOOD LUCK!