If you get downlights installed (IC rated), make sure the electrician doesn't pull the wires across the batts when installing the fittings, which will bunch up and create gaps/holes in the insulation.  I came across this issue on a skill-ion roof, and unless you remove every down-lighter to check that there aren't any holes and then redistribute the batts, you could end up with  thermal holes in the ceiling insulation and heat loss.