So here is what I learned.
  • Ram ProMaster is the widest.  More mechanics across the U.S. are more likely to stock replacement parts than for Mercedes.
  • Ford Transit: more reliable & popular than RAM, several model options.
  • Mercedes Sprinter has rear-wheel drive, often has rust problems
  • Chevy Express: easier to find
I'd LOVE to get a 4x4 to go moreover moderately rougher terrain and not sweet it too much. I like to accidentally run over things.

Anyone know what this cost looks like and what is involved??
I know adding a penthouse is about 10k, which I will definitely want.

Here is my wish list and initial priorities
  1. to sleep in it overnight or for a weekend on our private property with 4 dogs or a short weekend away. So comfy bed, temp control, wifi, microwave. the 4 small dogs - which initially can be with us in a queen bed(ideally)
  2. for it to feel like a 3 seasons room - to be able to open it up AND have full privacy when we want. 
  3. Our 10.5 acres of half wooded land is 25 minutes from my current condo.   So no immediate fridge, Shower, toilet, stove (we can bring food and coolers, cook outside with camping stuff, and shower at home bc it's so close. Our property has a septic system and electrically wired in but I have no idea about any of those things.
If you were to ask about the budget the only answer I feel like I can give right now is it depends on how many items the end product checks off my dream list. I'd love to start with something I can continue to pimp out. So say $20k-$50k

ANY van owners want to steer me towards or away from one of the above??

Wow! I know virtually nothing about van life...but am excited to hear more about your adventure as you move forward. 
I love it! I think the 4x4 is a great idea, but maybe it's not a must for your first adventure van? I'd definitely want it on my adventure van though, specifically because of how I'd use it.
Are you planning on converting it yourself, or will you have a company do it for you?