Rather than guessing and getting stuck with something that don't fit, look at something in stock or try another shop. Sure you may not get a trek but you will get a bike that fits. I am not too sure about consumer law in
PR.
When you buy a bike the most important thing you are buying is service from the dealer. If a dealer cannot give you a test ride on what you want you would be better off going somewhere else or getting something else. Well, unless you HAVE to have a Trek.