Just some pointers since I've driven B-vans for a long time now...
The front suspension on the '98 and the '01 that I now drive can wear if not taken care of. My work doesn't seem to understand the "L" part of an LOF (ie, Lube, Oil, Filter) and I get the occasional noise and a lot of minor drift, and that's on a vehicle with less than 70,000 miles on it. But, it hasn't exactly been taken care of properly either, and I'm probably the fifth driver.
The '97 2500 that I drove was pretty awesome for turning radius, something not good on the '98 or '01 3500 Maxiwagon. The '84 Royal 350 Maxiwagon also turned tight. I suspect that they reduced the turning radius for the revision that came out in '98, as there had been some fairly high-profile school sports team and church group crashes, and making the vans not turn as sharp seemed to be a way to make that less of an issue.
The '97's stock cupholders suck. A lot of conversion vans and RV camper vans have an aftermarket wood structure to make them better. I suggest looking into that and finding or making one.
Exhaust manifolds sometimes have issues on the vans.
The '97, in my opinion, is the last year where the driver's position was good. Later years they put a bigger dash in that moved the driver and passenger rearward. This is most a problem in the cargo vans without side windows.
The non-tilt-wheel '97 and down can be annoying but one can get used to it. I never drove a tilt-wheel version in those years to compare.
Much of the suspension stuff is interchangeable with the D-series trucks from '72-'93. Some people have even made 4wd vans by switching truck suspensions and axles in place of the 2wd stuff in the van.
Parts are easy to come by, as the basic van remained almost the same for 30 years. Plus with the conversion van craze that had been around for awhile, luxury upgrades are available.