You might want to fit a clutch while your at it!! Get the concentric also!
Gaskets nil! Only thing is a cam cover seal! There is a variator (variable valve timing) on the inlet cam that makes a rattling noise similar to diesel knock if its knackered(on cold start up)
If you have a complete engine, you can just about do it through the engine bay< but I normally drop old engine and box out the bottom!
Plenty of threads on here! Do a search for variator, timing blocks and twin spark engine!
Welcome and good luck!!