As far as stabilizers go, some people love them and some hate them. I have used them on my last Fifth wheel (SOB) and was not pleased. I upgraded to the JT Strongarm stabilizers and they really helped reduce movement.
http://www.lci1.com/jt-strong-arm#products
The tires will really depend on the rims you have installed. If the rims are rated for 110 psi and you just want peace of mind, you can go with the Saulin or Goodyear G614. If the wheels are rated for 85 psi a good LT tire should work.