CNG conversion on a 1996 Ford F250 2WD?

I've been looking for a truck so I can pull my horse around, and I found one I like, but I'm not sure about a couple things. It's a 1996 Ford F250 2WD that has been converted so it can use both gasoline and natural gas (CNG). I'll use the truck mostly to drive around my small town, and only to pull a small trailer occasionally. This truck has been used mostly in a fire department, and only has 71,000 miles on it, and it's in very good condition. I'm mostly concerned about how CNG might affect towing capacity. I'm also a little worried about 2WD. I live where it's snowy from November to March, but I would do most of my hauling in the summer. However, I need something that could pull a trailer in case of emergency in the winter as well. Does CNG cause problems in converted vehicles often? And is 2WD worth the low price when I won't be pulling a trailer often? The seller is asking $4,999.

Buy Snow tires for the winter, studded if it gets icy where you live. 2WD is fine. You can add some weight to the bed.

With cng, you lose a little bit of towing power, but not much. You can switch it to use gasoline when you tow if you want. The engines last forever because cng doesn't destroy them like gasoline does. Stick good snow tires on it in the winter and that should help somewhat, although most pickups and snowy, icy weather don't like each other much, anyway. Make sure you are near a place to fill up with cng, by the way, since stations can be few and far between. The good part is that cng is really cheap compared to gasoline in many places. It's only $1.65 where I live right now, and gasoline is $3.50.

CNG for towing will be fine. 2WD for towing will be fine. Torque maybe less on the CNG. If there's switch to switch between gasoline and CNG then great otherwise the torque will only be like 15~20% less.