The B14’s are super smooth, and having had the van on 30mm Eibach springs on standard struts previously, the difference is night and day. I found the lowering springs made for a “crashy” ride that was not overly comfortable. The B14’s on their own do a lot to eliminate body roll (but that could be because I have them wound right down as well), but there is a little bit that can still be felt, but it is 80% better than standard suspension. I have not got H&R ARB’s yet, but it is a route I intend to go, just because I want a very planted car like feel. Everyone who has both ARB’s and B14’s say it is top notch.
I run 18” rims currently which aids the comfiness of the ride. A 20” tyre is always going to leave you feeling more bumps in the road simply because there is less cushioning effect produced by the sidewall with it being far narrower.
It really is down to personal choice as to the look you are aiming for as to whether you go 18/ 19/ or 20 inch rims. Just be prepared to compromise a little bit of comfort with bigger rims and elastic band tyres. As to rubbing, it’ll be down to a combination of wheel choice, getting the correct sized tyre (more an issue if you have a T32), your ride height, coupled with the offset of the rim.
There are a huge number of threads and posts about wheels and tyres and offsets. Have a browse of those and it may help answer a few of your questions as well.
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