There are cans made to be installed safely in insulated ceilings and rated as such. They are IC cans. They take a maximum wattage that is determined by the trim you choose, usually 75 watt max and could be an R40 or R30 or Par halogen bulbs 50 watt. You have to go by manufaturers recomendation.
As for is it worth the expense that is something you would have to decide. If laid out properly recessed cans can really make a room.
Here is some pictures if you'd like to get some ideas.