Anyone know what type of resins I should be using for a fuel tank? Is there a fuel resistant resin or coating. I intend to make it out of fiberglass!
Try the search feature as it has been discuss several times. 
If you don’t find it on search - look for CARBOLINE – its what they coat the refinery tanks with (inside) up in Northland. If you’re in that area - I can point you to a distributor (well 3-4 years ago). Its an epoxy paint.
2 colors Red and white. First red several layers - then white - will help telegraph the spots you missed. Also - I recommend ATL in Auckland for ITW Plexus - use it to bond 'glass angle strips to the top then tape the top edges . Too many details - but that oughta get ya down the track.
Cheers - Jim
thermoplastics? PEEK, PEKK, and PES are pretty everything resistant, plus are great for impact resistance, vs thermosets 
Once you MAKE the tank, there are coatings you put on the inside, sold in most bike stores.
Will POR Brand products bond to the laminate/resin though?
no idea, best you ask them directly. They SHOULD be able to provide the answer.
From what I gathered when I was looking into tank liners the consensus was that the “kits” they sell at bike stores and the auto performance shops fail to stand up to the long term effects of oxygenated fules. I was not able to find a single consistently good review of the “available at store brands” POR, Gold Standard, Redkote… that actually showed reliability, there was way too much variablility in their longevity for my liking, especially on something that I want to last and not foul up my Fuel injection system.