The PVI Shocker is identical to the standard Smart Parts Shocker from '95 or '96. Smart Parts designed the Shocker and Max-flo and PVi built them. The sad part tho is that PVi screwed it up and Smart Parts fortuanately took control of production. Nothing has come out of PVi since.
If you wanna get technical, there were several electros before the Shocker or Angel. Wasn't there a long running rumor of an electronic Phantom or something too? Oh well, commerically speaking, the shocker was the first electro. The Angel came out within months.