Ultimate design spindle head

I am thinking about designing a totally new spindle head and drive. It
seems to me that most inexpensive imports are much too heavy on the low end
speed, with RPMs down to 100 or less, while very weak on the high end. I am
leaning toward throwing away the low end in favor of high speed and
simplicity. A 4 step pulley, in combination with a VFD could produce full
power at 400 to 5500 RPM if the native pulley system were to produce 600 to
2500 in four steps off a 1725 motor. This puts tasks like deep 1" hole
drilling off the machine and onto a drill press, but I figure that task
belongs there anyway. Any opinions on this?

G. Jackson