Using Vehicle Axles

I have been looking at axles and a previous post got me thinking, maybe what I should be looking for is an axle out of a Caravan. They have about a 5" drop, would come with springs, shock mounts and possibly wheels and tires.
A few of benefits would be that the axle width between my Caravan and the trailer would be the same.
The spare tire I can use both on the Caravan and the trailer.
The drop axle would keep everything lower to the ground. (not sure if that would be a benefit, although then I could make the trailer a little taller)
Has anyone used one of these axles before?
How about utilizing the brakes? Would it be very hard to convert them to electric brakes?
A few of benefits would be that the axle width between my Caravan and the trailer would be the same.
The spare tire I can use both on the Caravan and the trailer.
The drop axle would keep everything lower to the ground. (not sure if that would be a benefit, although then I could make the trailer a little taller)
Has anyone used one of these axles before?
How about utilizing the brakes? Would it be very hard to convert them to electric brakes?