Opportunity knocks in Clinton (aka Hell's Kitchen)     You can buy this open plan loft-like home with 9'.8" high ceilings and solid oak hardwood floors, in excellent, move-in condition.     The kitchen cabinets were custom built by Karl Schneider, cabinetmaker, who also built cabinets at MoMA. His shop was on located 49th Street adjacent to this coop's backyard. The kitchen drawer and cabinet door pulls are custom milled stainless steel.    The bathroom has Turkish limestone tile and custom mirrors. All hardware and shelf are by Michael Graves.     There is a Murphy Bed cabinet and closet also built by Karl Schneider.  The bed/closet cabinets are clad in seamless, floor-to-ceiling oak veneers and have European hinges.     This high first floor, floor-through apartment with south and north exposures has views of the neighborhood community garden.  Enjoy a quiet respite in the coop's communal garden.      This HDFC coop has income restrictions as follows:  $54,090 for 1 or 2  residents.  $63,105 for 3 or more. Cash purchase only.