Forget about all the recent hype concerning highboys and tea tables of American provenance. When it comes to fancy antiques, the New York market is dominated by two categories: English and "Continental" (i.e., French). Each school has its temple of worship: Dalva Brothers, on 57th Street, caters to the pro-French crowd; Devenish & Company, on Madison, is where Anglophiles shop for heirlooms. Flying in the face of this either-or aesthetic is H.M. Luther Antiques (35 East 76th Street, in the Carlyle Hotel, 439-7919; and 61 East 11th Street, 505-1485). What makes this uptown institution (founded in London in 1947) unique is that its clientele's taste is more eclectic but no less discriminating. Every period, from neoclassical to Baroque to mid-twentieth century, is covered -- co-owner Dan Harrison is interested in "striking, unusual, and very stylish statement pieces that embody that undefinable it." Top designers from James Huniford and Stephen Sills to Peter Marino to Albert Hadley have been spotted cruising the aisles of the uptown flagship store. Purists may scoff at such a radical mingling of genealogies and epochs, but Mario Buatta regards H.M. Luther as the definitive New York antiques store. "Dan has an incredible eye," says Buatta. "Even if it's something as simple as a pair of wall brackets, they will be the most interesting, most exquisite pair of wall brackets you've ever seen."