I have a copper head gasket on my corrado and was having the same problem you are having with it leaking. It is extremely hard to get it to seal because the head bolts tend to stretch and what not and compression leaks from all over and stuff comes out but once it seals its the best thing ever. Like the other people are saying get your head resurfaced so you can make the most tightest seal ever. Im serious they are the hardest things to get sealed correctly. An yes no sealant is the way to go, you just need to get it sealed in the first place without it.
And I feel your pain because I went through the same thing and it gave me the biggest headache for ever till i got it fixed.