As far as the stainless O2 goes, you still use your stock donut gasket.

 

I'm very happy with my Buschur ported/coated exhaust manifold and Buschur coated stainless steel o2 housing. Fitment of the o2 housing is perfect; I had zero issues getting it bolted up to my turbo and downpipe. The Buschur o2 housing is the exact same as the Megan except it comes ceramic coated and doesn't have the Megan name plaque on it. To me, it was worth the extra ~$80 or so to have it coated but thats up to you. You may also be able to buy the Megan o2 housing and have somewhere local coat it for you cheaper than $80. I also cut my stock o2 housing heatshield to cover as much of the new o2 housing as possible all in an attempt to keep engine bay temps as low as possible. While installing these two parts I also ported the turbo hotside; I really wish I would have gotten this ceramic coated too though.

 

So if you're upgrading to the Megan O2 housing, you don't have to buy any new gaskets?

 

The Megan comes with a new turbo to o2 housing gasket, but I'd personally just reuse the stock steel one since the material the Megan one is made from is known to burn and blow out. I'd also reuse the stock downpipe spring bolts instead of the Megan supplied ones. You also need to reuse the downpipe donut gasket.

 

Buschur/Megan are the same housing, the BR one is ceramic coated though. You use whatever gasket you have, stock, or like me the TXS one, or with Buschur the flat one. Just reuse whatevers on the car now.

 

Reuse the OE gaskets... I've reused mine so many times it's not funny. Do not use the Megan gaskets north of the downpipe!

You CAN NOT go wrong with Buschur parts... I always suggest his ported OE manifold as a best bang for the buck, and most durable option.