RE: TPMS
And these TPMS setups are not that expensive.
And for the truly paranoid here is another thing you can do about
wheels/tires.  And bearings.  I have a small (palm size) IR temp meter.
When I remember to, at a rest stop or getting gas along the way, you can
check the temperature of the tires AND the hubs!!  If you have a bearing
going bad it is going to usually show up as hotter than the other hubs.
Don't ask me how much, I've never found a bearing going bad that way yet.
But it gives a little peace of mind to find the temps are uniform, no one
wheel running much hotter than the other. BTW, if running for a long time
with just one side of the van facing the Sun that side will be hotter.