Mate.......break out those drill bits and pop those cherries!
Go the mini K&N style breathers. The chrome cap ones are

. If you ant to go real schmick and keep with the theme, go the Ford Racing ones! I have one filter and the PCV valve connected on the other side. DON'T confuse which side of the rocker to drill the holes (front or rear).
Start your holes small and work bigger - I porked one and went a bit too big. Scribe the exact diameter and drill lots of small holes around the inside of the circumference to knock out the disc. Then use a dremmel style grinder for a nice smooth finish.
Use some good loctite on the screws that hold the splash plates in place (that go under the holes).
For the two bolt holes on top of rocker cover, you can either buy extra long nuts or I used a big length of "thread rod", screw it in with cover on and cut so about 5-10mm hangs out, then attach chrome dome style nuts.