Another reason why you might want a front hitch would be to allow you to use
a winch that mounts in the 2" receiver hole.  They make these for Jeeps and
alot of Jeep people like the removable winch.  That way you can take it off
of the vehicle normally to keep it from being stolen or exposed to the
elements.  And when you need it you just mount it and plug it in.  If you
need it in the front you mount it there, or if you need it in the rear you
put it there.  That simple.  I would think that the front mounting would be
pretty easy since there are several large structural members up there.  Just
a matter of taking the van to a hitch place and telling them what you want to
do.  Several places in the web sell 2" reciever bike racks just do a search.  
Hope this helps.  

Thanks,
Ken Wilford
John 3:16
www.vanagain.com
Phone: (856)-765-1583
Fax: (856)-327-2242