Try contacting companies that make dirt track frames, ie: Champion, C&J, and such. They make lightweight frames with the geometry you have in mind.
Steelheart- '03 Speedmaster Black/Yellow
The Hayabusa Killa
16" Shorties/140 mains/Airbox drilled
Procom CDI
"There is no cure for Celibacy. But we can treat the symptoms."
