I wondered why the thread title said 18.5's.
IMO, if you're planning to "drive hard", I'd go with 17's. 18's look too big on the GVR4 and there is really no performance benefit to such a large wheel size.
Considering you have a 5lug swap done, you already have a much better selection to choose from over those of us with 4lugs. You should be able to find anything you need with the correct sizing and backspacing pretty easily. And spacers aren't that big of a deal if you really need them. As long as you're not spacing the wheels out a ton. Something like a 5mm or 10mm spacer will be fine.