Welcome to the group.
We used to have a Lil BigFoot, here are some pics of the work and mods we did, feel free to steal anything of use:
The Best 13 Ft RV On The Planet by Robert Miller | Photobucket
About headliner. I have replaced or repaired at least 6-8 headliners in FGRV's and I always use a professional auto upholstery headliner spray glue. Ask at a local auto upholstery shop what they use and where to get it. Most of the name brand products (the stuff at auto supply stores) haven't done well in FGRV's.
Your BigFoot has a bit of a linage. There were only built until about 1998, but I have been told that the molds that BigFoot used started out a Boler
molds, and now the BigFoot molds are being used over in Vancouver by a new company to build yet another version. I am sure someone will chime in with a name of the current builder.
Be sure to ask lots of questions.