Odd they do not answer the phone, but I have emailed with Vince a couple of times. Here are a couple of things he said:
We do build it in a off road version. We have 3 different versions of off road. Rock crawler +$3000 , off-road lifted(leaf spring) axle +1050. Off road torsion bar.+250 all wheels and tires are not part of add on price.The off road NestEgg trailer will be on off-road.com and extreme RVs. So keep your eyes out for that. I will email when it comes out should be the first of July sometime.