I would recommend looking into some of the new small hopper spreaders that have recently become available. If you have any room in the bed of your truck these work well. If not then you may have to go with a "tailgate' type unit. With these I would recommend going with a two stage unit as they will allow a wider range of materials without clogging.
The airflow is an excellent unit. It operates more like a v-box in that it has a small conveyor instead of an auger to feed material. Operating on an electric motor the unit is lightweight and easy to mount and operate. Downeaster makes a very similiar unit that works in the same way. The only drawback with these smaller units is that material must be loaded more frequently into them.
I have a single stage spreader. I have not had a want or need for a two stage (just my experience). If you are going to spread salt and sand together, spend the extra money on the two stage. Otherwise, a single stage will do you just fine at almost half the price. The guys out east use sand or mix (there advice is very good for their locations, but less appropriate for ours) whereas I've never seen anyone other than DOT put out sand or cinders.
If you are worried about material feeding improperly (which I've had no problems with, even in pouring rain with the lid off) get a vibrator (kit) installed on the unit. Mine doesn't have the vibrator.
No matter your choice, wash it out after EVERY use and keep the motor greased well if there is a zerk.
I own a pair of "tailgate" single stage spreaders. A Buyers low profile unit and a fisher. Personally I like the buyers better as the sides are on a 45 slope all the way and material seems to feed nicer thru it. We use only salt around here, so as posted earlier that will influence what you get the most. But as far as using straight salt I've had good luck with just these single stage units without a vibrator unit. I am thinking pretty hard of going to a small V-box this year although, but mostly just for greater capacity. If you're only doing drives I think your on the right track, and you'll get lots of feedback here as to what experiences everyone has had with different models.
I've got a Western Pro Flo 2, and have had great luck with it, as well as good performance. If you want to take a look at it, let me know. You're not too far from me.I'm probably going to dig it out of my garage this weekend to start cleaning & greasing everything.