I would definitely consider an electrical management system such as Progressive Industries EMS. These provide protection for a variety of conditions that a surge protector doesn't such as high/low voltage/frequency, open ground, polarity, etc. Having a smaller trailer I use a portable model but if you have room you can also get a hard-wired model so it doesn't disappear on you.
I'd also recommend a dogbone adapter. These come in handy if one of the outlets isn't working or is perhaps too loose.
Also, find out what kind and size of fuses are used for the 12V system and make sure to have spares on hand for those as well.
TT: 2015 Jay Flight SLX 195RB Baja Edition
TV: 2014 RAM 1500 Bighorn CC, 5.7L Hemi, 3.21, Factory Air Suspension/Tow Pkg, Andersen WD/SC