There is one front suspension, based on the equipment book. All three use a MacPherson-strut/control arm style front suspension supported by standard straight coil springs with a stabilizer bar.
There are three rear suspensions, all fully independent with the common elements of being a semi-trailing arm location set up with basically rigid differential mount and flex joints at both the wheel and differential ends of the half shafts, and are all sprung by coils (rather than leafs, torsion bars, air springs, or magnetoheroelogical springs).
This system was developed by BMW for their Neue Klasse four cylinder cars (1600/1800/2000/1602/1802/2002) and first adopted by Mercedes on the W108 S-class. It was the standard for independent suspensions from BMWs adoption of it until it was rendered obsolete by the Mercedes Multi-Link first introduced in 1983 on the W201 190. Semi-trailing arms are used in the van because they are flat and can provide independent action without intruding into cargo space- a multi link could not.
They use a barrel-type coil spring. A barrel type spring has a varying diameter to its coils, getting larger diameter towards the center and smaller diameter towards each end. This provides an ability for the springs to compress beyond their frequency (that is, lower and upper coils can move within the more central coils) increasing the available spring travel. The drawback is less precision and a lesser willingness to lateral movement, creating a stiffer ride.
They vary as such:
1) Cargo van, code CF0- it lacks an anti-roll bar, and uses a reinforced barrel spring, maximizing weight loading- at the expense of handling and ride.
2) Passenger Van Standard, code CF9: it also lacks the anti roll bar, and uses "reinforced" barrel springs, but different shock absorbers. My assumption is the shocks are modified to provide a slightly softer ride, but this should not actually affect overall travel or weight capability.
3) Passenger Van Comfort, code CF7: it uses a non-reinforced barrel spring, softer Comfort shock absorbers, and includes a rear stabilizer bar. This allows you to soften the suspension without increasing roll. Because of the less reinforced springs and the softer shocks, i'd think it has less theoretical capacity.
However, I would assume that since it's tow GCVW is 11.7k, and is it's GVWR plus its theoretical towing ability, I would assume that either vehicle can tow quite easily. It can only support a 500lb tongue weight, remember.