CONTEMPORARY, CHIC AND COMFORTABLE... THE IDEAL FAMILY TOWNHOUSE   This gorgeous, sunny 20-foot wide brownstone with stoop and bay window in front, and rear glass faade, is on West 76th Street, arguably the best West Side tree-lined park block, steps from Central Park. Completely gut-renovated under the direction of brilliant designer Lucien Rees Roberts, there are five stories plus basement, five to seven bedrooms, two terraces, a roof terrace, and a landscaped garden with fire pit and basketball hoop. In addition, there is a beautifully renovated two bedroom apartment with separate access, a great option for guests, family, staff, home office or income production. A picture window wall system ensures that every floor is bathed in light throughout the day. Features such as six-inch bleached white oak floors, an eight-zone Sonos system, a six-zone HVAC, four washers and three dryers, and black locust paneling in the garden are just several of the numerous details that place this townhome in a league of its own.    Lower Level  This floor includes a powder room, huge storage spaces, mechanicals, supplemental laundry room, wine storage and a large recreation room.    Garden Apartment  A renovated two-bedroom garden apartment, with full kitchen and living and dining room, is entered under the stoop. There are six-inch bleached white oak floors, floor-to-ceiling south-facing windows, washer/dryer and two full baths. The south-facing garden is accessed through one of the bedrooms. Black locust wood paneling lines the garden perimeter.  A basketball hoop, floating glass staircase, porcelain flooring and fire pit sets the tone: at once casual yet undeniably chic.      Parlor (Second) Floor: Downtown Meets Uptown  Twelve-foot ceilings soar in this dramatic parlor floor that incorporates the kitchen, dining room and living room in an open contemporary plan rarely seen in brownstones. Light streams in from the bay window on the north and floor-to-ceiling windows on the south in this loft-like layout which is at once stylish, luxurious, and still comfortable, functional, and durable. The uncomplicated flow is designed to maximize interaction of family and friends for cooking, dining, and congregating in an incredibly beautiful environment. The fully integrated white kitchen with Carrera marble countertops, two sinks and insinkerator, Sub-Zero, Miele and Wolf appliances, and breakfast bar seating is open to the living room where the fireplace