I think the reason you may not find a car/truck/rv stereo with a headphone jack is that it is illegal to drive with headphones on in a number of states. I got an inexpensive stereo from amazon.com for my RV that has AM/FM/CD/Weather/Aux, USB and SIM Card input:
http://www.amazon.com/gp/product/B004HJ21SO/ref=oh_details_o01_s00_i00?ie=UTF8&psc=1
2006 Four Winds Majestic 23A