You can tow those easily with your van.
My advice...find the best example of a boat that fits your needs, then have a PPI done at a reputable shop not affiliated with the seller.
He will do a compression and leakdown test, inspect the hull, transom and all electronic functions, look for soft spots on the floor etc, check the trailer, bearings, tires and brakes if applicable. He will then give you a list of things that the boat needs now and a list of things that it might need down the road and how urgent anything is.
Then you can determine if the asking price makes sense. ie is it already priced with that stuff in mind, or is it priced as if it needs nothing yet needs a bunch of stuff that can't wait.
Then STILL be prepared for the ongoing and unforseen 'gotchas' that come up.
My opinion, like others have mentioned. Find the best 16'-18 aluminum, with the best running outboard you can. Harder to hide fiberglass and wood problems and general rot with an aluminum boat.