What investors stand to gain from advanced-technology shares--""a once-in-a-lifetime opportunity,"" according to New York Times columnist Metz, for stock-market profit in the '80s. True, Metz tempers his enthusiasm with caveats, plus sound advice on building a balanced portfolio, recognizing true growth issues, and heeding sell signals. But this is not for the inexperienced or the impressionable. Metz's shopping list focuses on fledgling companies that produce or use microprocessors--manufacturers of a range of goods from hand-held calculators to robot assemblers and satellites, developers of special-purpose software, suppliers of such services as payroll preparation. Also, certain sidelight domains with commercial potential--notably, Texas Instruments' experimental photovoltaic cells, which might someday make solar power an economic proposition. At the close come capsule analyses of 32 select ""future stocks""--from Alpha Industries (microwave componentry) through Vishnay Intertechnology (precision instruments). Knowledgeable observers of the microelectronic scene will find little that's new here, and neophytes will find no mention of some of the built-in hazards of future-industry investment. But for cautious browsing, the book does pack a lot in.