Your needs are simple, really. You're looking for the best price on that amazing new Sony Discman that has 62-hour battery life. And that sweet Pioneer CD recorder that lets you burn your own CDs (cassette-tape mixes are so late-nineties). And that seriously fierce Toshiba 6-Disc DVD changer. Not to mention that FireWire-ready Canon digital camcorder (your iMac DV needs a playmate). Good thing there's one place that can take care of all of your tech-toy needs: J&R, indisputable gearhead mecca. Not only does this megastore's motley range of departments (spread over almost the entire string of storefronts on Park Row, across from City Hall) stock just about every imaginable electronic device in every conceivable category, but J&R often gets the coolest, most cutting-edge stuff weeks before other stores do. That's because this Manhattan institution does such high volume, and cuts consumers such good deals, that tech companies from Apple to Zoom trip all over each other to keep J&R happily stocked. (To do an end run around J&R's madhouse weekend crowds, call 800-221-8180 to get a free copy of the 200-plus-page catalog, or surf jandr.com.)