A SANTA CRUZ MAN HAS BEEN ARRESTED AFTER A DRUG BUST YESTERDAY (THUR).      25-YEAR-OLD ALEXANDER SANTIAGO-GONZALEZ WAS TAKEN INTO CUSTODY AFTER DRUG AGENTS SEIZED MORE THAN A POUND OF METHAMPHETAMINE AND BLACK TAR HEROIN.        OFFICIALS SAY GONZALES WAS A MAJOR SUPPLIER OF THE DRUGS.      A SEARCH OF HIS PESCADERO HOME RECOVERED OVER A DOZEN FIREARMS, BULLET-PROOF VESTS, AND AMMUNITION.