Congrats on being able to see the 'big picture' financially. There will always be another van, and i'm guessing after you find the right house you might just find yourself with another van of some type because they really are a great way to haul the family around. Hopefully after having your setup you have a good idea on what you can and can't live without next time around too.
I know when I was looking for vans, I was obsessive about it and was a Craigslist searching machine! Post it up - I'll bet someone looking will find it. However, with a 6 week old at home myself I understand how much free time you must have.
Good luck on the house hunting and keep us posted!