GO TO A BUILDING MERCHANTS AND FIND WOT YOUR ARE LOOKING FOR AFTER U FOIND JUST HAVE A LITTLE RING AROUND TO CHECK PRICES AND GET THE BEST DEAL!!! NOW IT DEPPENDS ON WOT SORT OF THING YOUR HAVING IN YOUR ADD ON TO HOW YOU SHOULD DO IT!!! BUT IF EVER IN DOUBT SPEAK TO SOME ONE IN THE TRADE JUST...