I didn't end up picking up a Saddle Tank in the SA group
purchase:

http://members.cruzio.com/~cikasper/sa/sa.html
http://members.cruzio.com/~cikasper/sa/pics/tank.jpg

But I did get a PDF file with a drawing of the tank and
brought it to a local sheetmetal shop. They said they could
produce a similar tank for $667 CAD ($445 US). If I did a
quanity of 4 or more they would knock $50 CAD ($33 US) off of
the price.

My question is... what modifications to the Syncro Tank would
you want to do in order to do the plumbing for a 2WD van?
Because the Syncro tank uses the 2WD filler, on a 2WD would
you "T" into the existing fuel filler neck? What about the
breather tank? Here are Bill's comments on the Syncro tank:

==============================================================

These are made by a Laser-cutting company in South Africa.
The tank dimensions are 1203 x 310 x 130 mm (roughly 47 3/8 x
12 1/4 x 5 1/8 in.); the inlets are 38 mm (1 1/2 in) & 12 mm
(1/2 in), the expansion/breather outlet 6 mm (1/4 in), and
the outlet 8 mm (5/16 in). They are supported by two flat
iron straps and use a 2wd vanagon expansion tank. The tanks
require you to fabricate strap mounting brackets, as well as
the plumbing. These tanks have 2 baffles in them.

Regarding plumbing the tank: The outlet and the vent are at
the rear of the tank (opposite the front end shown). One 2wd
fuel expansion tank can be fit in the front wheel arch, to
which is attached a fuel tank breather (or breathers). The
expansion tank breather is connected to a small fuel filter
fitted below the headlights. The outlet is connected to a
Facet fuel pump (or any appropriate diaphragm pump) fitted
directly behind the tank; this is connected with a T-piece to
the thinner stock filler pipe in the right rear wheel arch.

==============================================================

Thanks,
Chris