I hear that people with less powerful 1JZ's also stuff the rep of the 7MGTE too! he he he
I've got a 7MGTE in a MA61, it layed down 300hp at the wheels last dyno run at Rigolli Performance. Stocker head gasket, never changed it. Just a re-torque on the head.
Make sure she's tuned very well with no detonation and the head gaskets shouldn't be a problem.
Go for it. It's a fairly straight forward conversion. Particularly if you want to do it all yourself.