I recommend a TPMS setup. No need to pay for replacements yet, and the setup will continue to work after you finally DO need to replace the tires. No matter what you buy there is a chance of a blowout and the resultant damage to the trailer can be thousands of $$$.
I feel very confident with the pressures and temps displayed on the screen of out TST507.
2013 Passport 3220BHWE, upgrade axles, Kumho Radial 857's, all LED, TST507 TPMS, Reese DCSC, DIY corner stabilizers
2012 Ram 1500 Sport crew cab, Hemi, 4x4, 3.92 LSD, factory brake controller, S&B CAI w/scoop, Moroso air/oil can, 87mm ported/polished/knife-edged throttle body, Magnaflow exhaust, 180* t-stat, Rear lowered 2", Airlift 1000.