Problems with 2000-2003 Subaru Legacy head gasket?

I own a 2001 Subaru Legacy, 62,400 miles, that has just been diagnosed with a faulty head gasket which needs to be replaced. Subaru Sealer Conditioner has been added to stop the leak; however this is just a band-aid. The warranty on the head gasket runs out this March, but the warranty requires that I drive it another 30 days or 500 miles with the added sealer before repair will be covered. I have been given information that the head gasket problem is not related to the age of the car, but rather is a known problem to Subaru. The exhaust manifold gasket is also leaking and is tied into all of the work to be done if the head gasket is replaced. Needless to say, this is a very expensive repair, and I have been told by reliable mechanics that all of this is a poor design problem with Subaru. The car has been consistently maintained throughout my ownership, and this is the first major problem with the car. If anyone has experienced these problems with 2000-2003 models, could you please respond with details, suggestions, or how the problem was resolved? Thank you!

owned a 2000 outback ltd dealer put the sealer in the vehicle OK for about 5k miles then head gasket went approached Subaru about it and they said since it had over 100k and it was out of warranty we are not liable to fix it . even though gasket sealer was added to it. changed the thermostat 3 times even the radiator once hoping problem would clear up long story short don't take no for an answer from dealer tell them my vehicle is under warranty and a gasket conditioner is not going to help with a faulty head gasket