Thankfully, the shop I bought the wheels from, had spacers in stock. Otherwise, I mean, they are small spacers, so you can probably find some on ebay or something. If they were thicker and you needed studs in the spacers to mount the wheels to, then you need to be more picky in choosing the spacer. Not the case here.
As far as shaving down the spindle, it took them quite some time as they used an angle grinder to trim it down. Maybe the hub ring was getting in the way of them just straight up slicing it off with something else, but yeah it took a while. Maybe the shop you go to will have a better tool for the job. Otherwise, it's gonna take a while. Not hard per se, but seemed a little inefficient.
That number is the offset of the wheels. 40 being pretty conservative, and 20 is a bit aggressive. I had to go with the tire sizes I did since I wanted to fit as wide a wheel as I could to get maximum concavity on the front and rear. I won't lie, when I asked them if we could fit 10.5" in the front and 11" in the rear, I was very skeptical.
One thing of note though. You are stretching tires for this setup, not a ton, but you still are. That means chain shops like Discount Tire and stuff, won't touch your wheels/tires. Also, the whole load index thing. If you plan to have a crap ton of weight in your car for whatever reason, you are running a risk that the tires won't hold up. Just had to make sure I put that out there.
