no worries bigsmoke. i'm new here and am limited in knowledge, but i'll do my best to help. the dresser sounds like a good cab. as far as the intake/exhaust you can use a hole saw. or if it's on the back maybe it's just thin backing. either way it won't be a big deal. start thinking about the design now. try to keep the stealth factor (no exhaust on sides etc.). i'm not sure how hot a 150W HPS bulb gets but you should be able to make it work.

-shake