Couple of updates:
Block Erupter is Stable @ 447/1.2v~1.25 with relatively low heat dissipation compared to the previous ~1.4v
20mhz exceeds current limit and voltage regulator goes into overcurrent mode when mining begins.
18.43mhz crystal maxes out onboard regulator and does not produce stable results at any voltage over long periods of time.

I do believe the voltage regulator is damaged at this point I cannot get it to output a stable voltage even back @ 447/1.2v, it just goes into overcurrent mode. So I do believe thats it for tonight, I need to come up with a solution for a higher current regulator. At Least now I think we have a good voltage range @ 16mhz.