Truck tie downs/turn buckles - For a hardside 9' or 9.5' TC you'd most likely be looking at either HappiJac tie downs, Torklift tie downs, or a combination of the two. Some who are handy with a welder even fabricate their own.
Water capacity - You'll want to look not just at water capacity but also at the ratio of fresh water, grey water, and black water tank capacity. The size of tanks you need will depend on the number of people, their water usage, and how long you'd like to go between fills/dumps.
Propane - Propane storage is usually one or two 20 lb or 30 lb bottles. The 20 lb size is upright and you can either refill them or swap them out at a propane exchange center (although you'll only get 15 lb of propane that way). The 30 lb size is horizontal and you'll need to refill.
Air Conditioning - Most manufacturers install a 13k BTU unit which is generally overkill for the small space in a TC. Smaller 9k BTU units are available. A low profile unit will knock several inches off the height of the rig. You won't be able to run a 13k BTU unit with a portable 2k generator unless it is upgraded with a soft-start device.
Heater - Nearly all TC come with a propane furnace. They aren't particularly quiet or efficient but get the job done. For camping where electric is available you can easily heat a TC with a small electric heater. Some who camp a lot in cold weather with no electric hookup install a more efficient propane heater.
Fridge/Freezer (would like Lg. freezer) - Fridge/freezer in pop-ups tend to be small so if you want to larger size you'd need to look at hardside TCs. Even then the largest freezer is nowhere near as large as that in a residential unit. You could consider carrying a portable chest freezer for additional capacity if needed.
Electric jacks - If you plan to load/unload the TC from the truck with any frequency you'll appreciate these! There are two major brands: Reico Titan and HappiJac. Either brand will do. You can purchase the motors and legs for each brand separately but they are not interchangeable.
Outside shower - Unless you get an older unit whatever you buy will likely have this. Even if you don't actually shower outside, an outside shower feature is handy for rinsing off your feet, washing a dog, etc.
Maybe this will help. As others have stated, do some searching on this site and take a look at threads in the TC University sticky. More specific questions and some description of how you plan to use your TC would help the folks here help you. Happy TC hunting!
2008 Dodge 3500 DRW 4x4
2008 Bigfoot 25C10.4
Torklift/Fastguns/Hellwig/StableLoads
