This sounds strange to me thai. I don't know of anyone that has had problems, but I DO know that of at least two members, that have them mounted no problems.
ElektroBeatz has the 17", 40mm offset mounted.
6g72tt also has them, but in 18" I'm not sure what offset.
Here's where we talked about it last:
http://www.3si.org/vbb/showthread.php?s=&threadid=52637
Our cars use 46MM normally.
If you come short on that, and get 40's, they'll be fine. The 5mm difference is actually 5mm that the wheel will sit FURTHER out of the wheel well. this translates to something like less than a 1/4" outwards. You won't notice.
The spokes on the Tantrums are VERY shallow. That means they don't intrude into the wheel area much at all. This prevents the caliper from smacking it while the wheel rotates.
I'd like to hear from anyone that found Tantrums not fit their car, what kind of car, and if you had any wheel mods (aftermarket calipers, etc)
Otherwise, I think you're fine with anything 40mm in the tantrum line. (stay away from the 45mm offset. I think that brings the spokes in too close to the caliper.)
Plus, I don't think there is an 8.5 width in any tantrum. Or at least according to Discount Tire:
http://www.discounttiredirect.com/dtd/findWheelSizesByBrand.do?step=sizes&index=11
so, the 18x8 or 18x9, either in 40mm offset will be fine.
Let us know how it turns out.
I personally plan on getting 17X8, 40mm Offset. (that's what Elektro has, so I KNOW they fit all VR4s)
Elton
*edit - Addded the 3si Thread URL*