I need spacer recommendations, please.

[Shawn Stanford]

I've poked around, but as far as I can tell nobody else has done these wheels on a Boxster. I'm trying to get a retro kind of look, and I've settled on 16" 928 manholes. I have them on the car and I like the look. I'm getting some rubbing up front in tight turning, but otherwise no clearance issues. I'd like to push them out, though:



If I've Googled correctly, the stock wheels on a '99 are:

6J X 16 @ 50 mm (front)
7J X 16 @ 40 mm (rear)

And 928 manholes are:
7 X 16 @ 65 mm (all)

If I did my math correctly, I need 25mm spacers at the rear and 15mm at the front. And, looking at them on the car, that seems about right.

These are for street driving only. I'm going to pick up a set of 17s for track days.

So, here are my questions:

1. 25mm sounds like a lot. Is it too much?
2. I'm planning on putting on a set of H&R sport springs with a 1"-1.25" drop. Opinions on if this will lead to rubbing with the 25mm/15mm spaces?
3. Is there anything I've forgotten or should consider?

Thanks in advance!