Towing options

I am having to get a new vechicle to tow with. I have looked at a 91 s10 Blazer 4.3 engine, a 92 Cherokee 4.0 engine, a 91 Bravada with the vortec 4.3 engine. All seem to be comprable in condition. I know I would be better off for the towing with a truck but this also has to be my everyday vehicle and I rack up a lot of miles so I am trying to keep it on the light side of a guzzler when it comes to the gas mileage. Have any of you used any of these vehicles?
If so I would love some feedback. My rig weights about 4500 by the time I load it up.

Katy