Sorry for the late response. I got my locks from RVlocksandmore.com. I don't remember the length of the locks, but I know the one for the outdoor shower is a different size than all the others. Also, you can get them keyed to match your entry door so you only have one key for everything. Do a search for "storage locks" on here and you'll find more information.
Re: the digital thermometer - there are lots of threads on here about that as well, and several different models that you could use. Amazon carries several.
2015 Rockwood 2306
2015 Tundra CrewMax