honestly, the gen II has such an open hood the best bet is just a little something for the back to let the air back out, or maybe just make a mesh hood. but i cant help you for any manufacturers, i would just do some cheap custom stuff, can me made to look awsome for pretty darn cheap.
Not to sure if any company makes vent kits for the gen II's but SLP makes universal vents you can add or vent screen sheets in many sizes, or Fastlane Inc. makes some really trick universal vents you could utalize. Go to http://www.flaneinc.com/catalog/index.php?cPath=24&osCsid=85379866f7d71c580e8ad6a9ee459a21
These are the best aftermarket products I could find that you can add onto any sled.