Here is what I did to my SN21G5!
PF16 Mesh Cover
2x Blue Cold Cathode Lights
Top Blow Hole - 80mm CoolerMaster Fan
In 3.5" bay - Vantec Black Nexus NXP-205 Rheobus (for Blow Hole Fan) - I pushed it back a little for the front door will still close normally!
I cut the Blow Hole myself. I've done this on all my previous shuttles.