Hi, yes this does present some problems. first thing is finding out if drilling holes in the ceiling will weaken any structural soundness. if not, you can get shallow can housings with the proper ratings, and by useing an angle grinder with a diamond wheel cut a circle and "x" out the center, then use a rotary hammer/drill, slowly drill/chip away the hole. there are other methods as well but you simply need to weigh the cost of each. this would be a cheaper way. good luck..