FDM is a method of 3D printing, as is SLA. One is filament deposition, the other stereolithography, sometimes called MSLA for masked stereolithography. FDM or FFF printing has a variety of materials that can be used. PLA, ABS, PETG, nylon, TPU and a few more exotic types. MSLA uses a liquid resin which is cured by UV (or rarely, daylight) light and has fewer choices. There are casting resins designed to be burned out in the process of creating jewelry and other cast items. There are some variations in the hardness (and brittleness) of these resins.

I'd expect that if you are building a fifty-seven inch long boat that you don't need the detail level that MSLA would provide, although you'd have the capability for scale rivet heads on the metal bulkheads. Depending on the model, you could save a good bit by having the hull and superstructure made from PLA or other FDM material and having panels done with MSLA resin for the detail, then glue the panels in place.

There's a lot of flexibility in 3D printing and design that should provide you with the model you desire.

I'll pop you a direct message with an email address. You can send the model and I can respond more intelligently and less broadly if you can share the parts. I'm not in this for an income, it's just one of my hobbies. I like to have practical objectives for my 3D printing projects.