[MagicRat]

You should be fine so long as your van is equipped properly.
These vans are good for about 2000 lb stock and up to 3800 lb with the factory tow package.

This package is not essential; you can equip the van to match these specs.

Get the biggest hitch you can. I figure a trailer like yours probably weighs 1000 lbs on its own. Add another 1000 lbs for the beast and that's an easy 2000 lbs, obviously
However, a 2000 lb Class II trailer is not ideal. You should get at least a Class III 3500 lb hitch with a receiver (the square thing that fits into the hitch.)

A decent hitch place could install and set up the wiring too.
If the horse trailer has it's own brakes , then make sure they work properly and you have a brake controller. This is probably not essential for a 2000 lb trailer but will improve safety substantially.

Also, you must install an auxilary transmission cooler - again, get the biggest one that will fit. Do not skimp here; the number one cause for transmission failures is excessive heat.

Finally, consider getting air shocks or air booster springs on the back to better cope with the load, especially if the trailer has lots of tongue weight.