Thanks for the kind words y'all. I am really happy with the way it turned out, and it looks awesome in person. I'm not sure what has the most impact, the wheels or the lowering (I used KW coil overs). Either way, it makes me smile every time I look at it.
With regard to rear tire diameter, I've tested the speedo against my navigation device and it is DEAD on. To my eye, the diameter looks very similar in the wheel well and when the two tires are lined up against each other. I like the extra wide rubber when the Heffner mods do their crazy boost thing. More on that later. Overall, the only downside I can see right now is that it was so dang expensive...as the T-Shirt says, I hope when I die my wife doesn't sell my car parts for the price I told her I paid for them...