re: Does anyone recommend anyone in the Lafayette area that builds small metal homes?

You might have a hard time getting one company to do it all. You may need to have the building erected by say Bergeron Steel (or do it yourself kits from Mueller Steel) have it framed and finished by a carpenter.

D&M for septic work

Celestine Plumbing

Permit office is in Breaux Bridge

St Martin Parish uses (or did a few years ago) a Lafayette company for inspections and they were absolutely wonderful to work with. Wife and I built our own metal home and they went out of their way to help.