amp-man
You shouldn't have any problems with clearance above, as standard cans are engineered with only 1/2" space left above them to a wood floor above. I mean that the standard height can is 7 1/2" high which only gives you 1/2 inch (at best) above in a 2 x 8 ceiling. Same with shallow cans (5 1/2" in a 2 x 6 ceiling)
Some ventilation holes sound like a good idea.
Bill
