You can go with 12mm or 15mm spacers with stock wheels and tire sizes. 18mm, 20mm, or more will likely need fender rolling to not rub in the rear while 10mm or lower apparently require some minor modifications to the wheel hub (or so I am told).

I had a set of hub centric 15mm spacers from Burger Tuning. They came with black bolts too so that was a plus. You can find their 12mm and 15mm spacers on amazon too. VRSF also makes a set of spacers, they are a little cheaper but I can't find them on their website anymore unfortunately.

That said I personally wouldn't recommend using spacers. They are fine for most people but if you drive like I do you will eventually ruin a wheel bearing. Again it doesn't happen to everyone and maybe I had a pre-existing issue I exacerbated but I would suggest just getting the wheels with the proper width and offset instead of relying on spacers to get the look you want.

If you just want to get rid of the bolts then the kit JustCallMeMittens linked makes a lot of sense. I might get one myself! :D