Most manufacturers take great pride in the quality of the home the produce. But keep in mind that the home is only 1/2 the equation. Often overlooked and of great importance is the quality of the dealer and installation crew. Look for a dealer that has been in business for many years. Does he use his OWN installation crews, or part it out to bubba and his buddies (more common than it would appear). So many times a manufacturer is blamed for poor quality but was really a result of poor installation. Shop for a dealer just as you would a manufacturer. Even checking in other cities, especially larger cities. You may find the price considerably less expensive from a larger dealer, further away.
Consider checking with your local Better Business Bureau and see what complaints have been registered with the dealerships. Also check with Angie's List and similar website that deal with local contractors. Remember a dealer is the contractor of the the finished product, the home and the foundation.
There are certain products I would consider over others. Starting with the floor system, if you can afford it (and the manufacturer offers it) look into upgrading the floor decking to an APA Sturdi-Floor (same as a modular home would use). OSB is what's usually found in a modular, D-2 particleboard in a manufactured home.
Consider ordering bare floors and having a local flooring dealer install the vinyls and carpeting.
When installing skirting, more ventilation is better than less. In-fact if it were me, I would install all ventilated skirting. Skirting does nothing in keeping your home warming in the winter or cooler in the summer and if not vented properly will prevent water and excessive humidity from escaping.
Often see particular homeowners purchase a home with green nail gyp and then hire a local contractor to tape the seams and paint it after the home has been installed. Many people prefer painted drywall over vinyl-coated gypsum as it's easier to repair and keep clean. (And you can change the color after a few years if you get tired of it.)
In the wall system, 3/8" drywall is much better than the standard 5/16" & an exterior house-wrap is an well-worth it investment.
Windows are critical. I would opt for the best windows, vinyl over metal, insulated glazing over storms and a argon gas fill to limit the amount of heat passed into the home via sunlight. In modular housing, in the southern states, windows are required to have a SHGC rating (amount of heat passed through by sunshine) of 0.30, or less. Manufactured housing has no such requirement. If you can upgrade to their best window option (and we would talking several hundred dollars), it would be worth it over the homes' lifetime. Windows due to their nature are a major source of heat loss/gain and the better ones will repay themselves over the years.
For the exterior wall, avoid hardboard siding. Avoid it. Avoid it. Vinyl siding is OK (only with a house-wrap). (A house-wrap is required in modulars).
In the roof better shingles are usually worth the cost in longer life. Look for ventilation options (ventilation in the roof is very important, the more the better, your home will cool easier in the summer, heat better in the winter.)
In the electrical system, consider installing additional electrical outlets, based on furniture placement and not just code.
I would also recommend looking up both the manufacturer -and- dealer on the Alabama Manufactured Housing Association. (If their not listed as a member, why not?)
http://www.alamha.org/
The Alabama Manufactured Housing Commission is responsible for writing the regulations for Manufactured Housing installation, and their rules can be found here:
http://alabamaadministrativecode.state. ... index.html