The pen cameras (if not the shoe phones) of sixties screen spies are now available to every suspicious or just plain nosy citizen. Bo Dietl, who has done security and surveillance work for Harrison Ford and Evander Holyfield, among many others, favors Qüark International (537 Third Avenue, near 36th Street; 889-1808). "They have the best prices and the best technical stuff," says Dietl. "My favorite thing there is the pin-eye-lens camera, where the lens is in the center of a pair of eyeglass frames." The gadgets Qüark sells are legal, but Dietl warns prospective Mata Haris and Agent 99s to "make sure their use of it is legal." (Qüark will advise you about the laws.) One of their newest items is a bullet- and knifeproof raincoat. "You can take an ice pick and try to plunge it in," insists Qüark vice-president Gregg Graison, "and you won't get through that coat."