anyone recomend descent leakdown tester?

will a leakdown tester reveal whats going on? I understand not wanting to blow money on new heads, but i also dont wanna blow money on having the seals replaced and it still be leaking oil upon de-acceleation. And what do you mean swapping valve covers? you mean swapping the baaffles around? i'm going to run my breather on the front side of the passenger valve cover, and run my pcv valve on the back side of the passnger valve cover, and i still havent figure out what to do with the rear side of the drivers side valve cover... My brake booster is so close to it that i cant run a breather on it.... should i just plug it off? or try an run an open gromment in that side stuffed with some of that stuff they put in the oi breathers so that a little bit of air can get in thru there? I will make an appoinment to get my valve seals inspected, it should be obvious to a good mechanic if they are letting oil by, right? And if the seals are ok, then what? new heads? because i dont think i have an internal vaccum leak cause i get a steady 18 inches of vaccum, its not extremely steady, but it its not all over the place like a guy would expect it to be if there was a vaccum leak....