I sleep in the back of my 2 door and I'm 6'7". I have a sigle air mattress and it works nicely.

 

I think I'd prefer a 4dr just for easy access to the back while camping or putting groceries or gear inside.

Plus I really don't like that extreme back window slant on the 2dr...

 

the 4.3 is a great motor. you just have to worry about the trans. like Karcinagin said, you might want to look into a trans cooler. the one that is in the radiator isnt exactly a "cooler." more of a warmer. its for the ones that live in the cold weather. if you are going to be towing, i would get an aftermarket cooler.

 

I've found that wind drag has a much larger effect on the mileage than actual weight of the trailer. I've pulled a 5000lb cube trailer that is the same width and height as the Blazer, and it had very little effect on my mileage. I could use OD fine pulling that trailer, other than on the hills. I've also pulled an empty full-sized 80's pickup box trailer that is almost 2 feet wider than the Blazer and it killed the economy and power. The pickup box trailer weighs less than 1500lbs and I couldn't use OD at all; it was constantly shifting.