If you end up with that nice trailer, you'll end up with friends who wanna go with ya... get a crew cab, there also seems to be more of them to chose from, I had a hard time finding my ext cab...
The 4x4 will be nice for the extra traction, as well as the use of low range in the transfer case, I use it ALOT... just for the added control of going slow, nice for manuvering trailers I use often. Takes alot of strain off the trans and tork converter...