If you want the meat for another use, take it. Do the bones without the meat. I wouldn't waste perfectly good roasted chicken meat by making stock with it.
The bones, skin and scraps of meat left on the bones will make a fine stock. BTW, I usually use a mix of roasted and raw bones. I get the raw bones from whole chickens I debone or the backbones I cut out of a butterflied or quartered chicken.
"If you want to make an apple pie from scratch, you must first create the universe." -Carl Sagan