@ 500 Above: HA! Yeah, I know...I guess it's more of a theoretical question, but if there is something out there... Actually, after doing some research it is the warbird era that come closest to the performance (but the cost, ugh).
@AdamFrisch: Yes, actually I think Ted Smith's design is probably one of the better options out there. I have some time in the older 600A models, but never flew the Machen conversions. From everything I'm reading the Super 700 series is essentially twice of everything that the Lancair IV has, but at essentially the same speed up high.