Sounds like you're off and running, welcome to the madness.
-Interior trim work: best thing I did was buy an inexpensive pneumatic stapler. (already had the air compressor in the garage) Hitachi at Lowe's. It made re-installing the trim pieces a breeze. I also built my roof to wall panel covers with it, and I've used that stapler countless times on other projects since, can't believe I went all that time without one.
-Consider offsetting the windows, it lets in light in a normally darker interior, and creates a great crossflow if you put in a vent fan in the roof. I credit member Gonefishin with this idea, and it has been a winner.
http://www.tnttt.com/viewtopic.php?f=42&t=33924-On the reduced ceiling height, another user dealt with a low ceiling garage height by making small diameter steel circle plate rims to allow the taller trailer to get into the garage, then simply swapped to the standard wheels/tires once it was outside. By doing this he kept his interior trailer height. Spend a little time reading through this one for inspiration: (member pmspirito)
http://www.tnttt.com/viewtopic.php?f=42&t=45197-Still one of my favorites, simple, neat, well thought out, retro colors on re-purposed cabinets, I borrowed lots of ideas from this one: (member WA)
http://www.tnttt.com/viewtopic.php?t=40504Of course this place is full of inspiration, so much so, many times there's just too much to wade through and keep up with.
With that said, here's some Jeep-related builds for your viewing pleasure if you haven't already found them. (Don't forget coffee and a legal pad for notes)
http://www.tnttt.com/viewtopic.php?t=32431 http://www.tnttt.com/viewtopic.php?f=42&t=37621David