Chuck,
As I said before, my van came out great with no welding/cutting of 
roofs.  I was wrong about the roof sitting on top of my existing roof.  
The hole is alot larger than I originally thought.  It extends from 
behind the front seats all the way back to the front of the AC unit 
(where the rear speakers are mounted.  This gave them room to drop the 
pop top roof in place without changing the height of the bed (which I 
also miss reported earlier....).  My top is solid.  I don't understand 
the argument about it not being strong enough since Westfalia 
essentially does the same conversion that was done on mine.... In fact, 
the ridges in the roof are set up for the opening to be cut. 

I would be leary of firing up a torch and turning it on my van!
I paid $10000 (van + conversion) for the whole thing so I have no idea 
what to pay for a top.  I would guess it could be a $1000-$2000 for the 
top.

Chet
-- 
Chet Douglas - CRD Consulting - Peripheral FW,SW,and Drivers
(541) 754 - 1817