There are FIVE articles in the REFERENCE section on trailer selection and set up. The index to those articles is at
http://continuouswave.com/whaler/reference/trailering/If you read those articles you will have a good background for setting up a trailer to carry your Boston Whaler boat. They will encourage you to get a trailer with a lot of keel rollers. This is good advice but there is a problem: there really are no manufacturers of trailers today still making all-keel roller trailer--at least not for for larger boats. You may find a keel-roller trailer for a 13-foot; a trailer for a 13-footer would only have a couple of keel-rollers, anyways. Typically what has to be done is to buy a bunk trailer and add your own keel rollers to it.
There is also a comprehensive article about on-deck fuel tanks for Boston Whaler boats, again in the REFERENCE section at:
http://continuouswave.com/whaler/refere ... lTank.htmlI recommend reading the article and also following all the hyperlinks to additional material on the subject.
There are no manufacturers today making fuel tanks from fiberglass laminates and resins for ethanol-gasoline blended fuels. The ethanol-gasoline blended fuels have a unstoppable tendency to soften and dissolve fiberglass laminates in fuel tanks. The manufacturers that continue to make fiberglass laminated fuel tanks are usually selling fuel tanks for aircraft, and use of ethanol-gasoline blended fuel is prohibited in aircraft.
The most well-know manufacturer of fiberglass laminated gasoline fuel tanks was PATE PLASTICS of Florida. The appearance and prevalence of ethanol-gasoline blended fuel for boats has driven them out of the business of making marine fuel tanks.
If you are certain that your fuel will never contain any ethanol, you could continue to use a fiberglass laminated fuel tank, but you would be at some risk, in my opinion, given how easy it is to get ethanol in your fuel without knowing about it. The ethanol lobby has corrupted the fuel labeling requirements in many states in order to hide the ethanol content from the buying public. Be very careful if you use a fiberglass fuel tank. I would not.