There is some sage advice floating around on this thread, without a doubt. It's they way I've always pursued most hobbies and most certainly vans. The biggest thing, if you think you like the lifestyle, is to get one and get rolling! You can plan your uber-wicked $100k plus Sportsmobile or whatever after you learn what you really want. Anyway, I'm basically just repeating what's already been said so I'll quit but..........
As far as 'older' SMBs go, the interiors, appliances and tops of these things haven't changed much, well, ever. The upholstery is just different for the most part. I would strongly urge folks with it being 2017 to go with a 97 or newer Ford or Chevy if you can, I'm not well versed on Dodges. As for Sprinters the earliest ones we've seen are about 2005? so any of them are modern enough.
Here's why: These are big, heavy vehicles. Anything older than late 90's is going to be pre ABS, traction control, etc. etc. and is just not going to go, stop or handle anywhere near as well as that Japanese thing you drive to work every day. Sportsmobiles bring to mind long trips and offroad ventures for most, so try to go as new as you can but still not new new. I'm very happy with the late 90's/early 2000's Fords because they essentially haven't changed since then......at all. They are very comfortable to drive even for less courageous ladies or younger drivers.
Just a thought. That sweet vintage late 80's SMB might look cool but if you plan to put a lot miles on it you may regret not spending just a bit more.
YMMV