San Juan does have about 8 models of pools that are 15'-16' wide x 40'-45' long so it's pretty close. It used to be that fiberglass was the most expensive pool you could get but the price of concrete has gone up so a fiberglass pool, even with trucking in, is competitive with shotcrete and gunite in many markets. Part of the cost of fiberglass is how far it needs to be trucked to the site so if you are not to far from a manufacturer then fiberglass is a viable option. If it needs to be trucked a long distance then it might not be the most cost effective pool. It is a much more resilient surface than vinyl and just as inert chemically, and next to a completely tiled pool surface (expensive!!!) it is my personal first choice.