Cleaning the breathers should take a couple of hours for a novice to do, all you need ti do the job is a large can of carb cleaner and some rags, plenium off and a small drill bit to push through the breather box pipe hole.
As for the oil leak it could be anything including the cam cover seals, who changed them, yourself or a garage?.If they are not sealed using the correct goo it will be wasted money. cam shaft seals could be leaking too but untill you get the front stripped down you will only be able to guess at the leak.

You could also pm one of the mechanics on here and see if they can help you, they know what they are doing and their charges a very very competitive.