You dont want the megan gaskets. I just had to go to Sideways to replace Daves gaskets because the megan gaskets lasted all of ONE week.
Use OEM gaskets. In fact, for the downpipe, just re-use the stock ones. I have re-used the turbo to downpipe gasket like 10+times over on multiple cars and have yet to see one leak.
Ill call you tomorrow about the downpipe