It depends on many things.
What kind of van? full size or mini?
What kind of conversion? Lowered floor, Raised roof? Neither?
What kind of wheelchair? Big? Some only fit in one place
Try your wheelchair out in the van before committing to purchasing the van or the EZ Lock. Not all wheelchairs fit in all vans. Mine will only fit in a few vans.
I want to ride in the front. That means any solution that has the wheelchair riding in the middle or rear is an interim solution for me. I want to ride in the front so I have better visibility and so my wife and I can interact while she is driving.
Our van has the wheelchair riding in the middle. This works for now, because I can still transfer to the front. So having the wheelchair EZ Locked in the middle of our full-sized, conversion van with a raised roof works for me now.
When I lose my ability to transfer, I can still ride safely there, but I will not be able to see out the windshield of any windows, because my head sticks up into the raised roof portion of the van (we don't have a lowered floor).
We are starting to seriously look at a replacement for this vehicle, as it is inevitable that I will lose my ability to transfer. That replacement vehicle will have the EZ Lock in the front passenger location.
Be aware that you have more flexibility with EZ Lock that other systems. With an EZ Lock, you can have the wheelchair facing any direction with respect to the EZ Lock. With a Permalock (Permobil's competitor to EZ Lock), you can only have the wheelchair facing toward the front of the lock. The Permalock would not work for the mid van location we needed for our current van.
The EZ Lock bolt on the wheelchair does not retract, but the Permalock does. So, the Permalock is better in that regard.
Good luck deciding what to do.
Steve