To answer one of your Q.
I have 912 springs. I think not too many people with lifted VXs used any type of spacers, but I was advised, and followed with 1'' coil spacers. You can find those here: Independet4x or DOR
We measured as we lifted it, and it seems I got 3" of lift with this setup plus something over 1" height with my 265/75/16 BFG All Terrain. I did not change shocks, as I was told it wasn't needed.
The ride got stiffer, and I can feel limited down travel of the wheels, but nothing really alarming so far. I think the bigest problem I had with body roll - oh boy, cornering has became a challenge for a while, until I learned to slow down... LMAO

About your wheels and tires - I have no idea... I think someone else can help you with this... Sorry