One of my big hesitations on a 4x4 Sprinter was about the wheels. Most of the wheel packages I have seen look like the wheels are too small. Dinky. So I spent a ton of time researching what to do.
I'm (for now) opting out of the lift kit. The van already has a pretty high stance and I don't prefer to mess with factory suspension geometry, if possible. If I do at some point get a lift I'll go with VanCompass and have the Santa Rosa Mercedes dealer do the install, they do that.
If you look at this chart:
You can see that some pretty fat rubber will fit. Up to 285/75/17 = 33.8" X 11.2".
I will be adding 16MM spacers and an Own Van trim kit, both of which are simple and add a bit of muscle to the look and stability.
For rims; BLACK RHINO ARSENAL WHEEL 17X8 6X130 - 38MM OFFSET - SAND ON BLACK
In the pics I found one van with a low roof and no lift (like mine), but with smaller rims/tires. The other high roof van has the rims and tires I'm ordering, and might have a lift.