I can't seem to find photo-metric data to calculate the beam size of a 500w Par 64 for a 20 foot throw for the 500PAR56NSP and/or 500PAR56 WFL anyone Know where I can find it ?

Good question.. that would probably be on the website for of the lamp manufacturer.. say, if the lamp is from GE, then it would be on GE's website.
If the lamp is osram then it would be on osram's site..