Measure twice. Trailers usually use a smaller size tub/shower pan than is used in stick built homes. There are several places around Little Rock that sell mobile home fixtures.
They ain't cheap. If you can use a standard size, then you can buy what are called remodel units. These are multi part units that snap together. Don't get the ones that bolt together as they are hell to put together in tight quarters.
Sterling makes some very nice units that snap together. All the joints are self draining so they don't leak if properly leveled and installed per instructions.
Quit complaining about the color, just pull up your skirt and fish! -- snagged