OEM is perfectly fine provided your not going above 12 psi and you have installed it correctly (ensuring the head and block surfaces are prepped properly).

Past that, I believe it all depends on what you did/do. If you have to shave the head, you will need to go with a thicker headgasket and at that point I think you want to go metal. Also, would recommend the ARP head bolts just to keep you on top. If everything is prepped properly you should have no issue.. but its not a cookie cutter answer, because each HG is built for a different purpose. (my thoughts)

oh.. and start your own thread rather than tagging onto one. Makes it more likely to get the desired response.

dunno why you all say a novice mechanic should not do a hg.
there is only one way to learn.
i started all my learning on my 85 celica supra and my 86 suzuki samurai.
of course i had done 2 engine swaps and alot of other repairs before going near a hg

hg is not that big a deal, you just need a manual, and the tools, and when dealing with a 7m a friend to help you get it over the hood, because that thing is heavy...

just did my 5m hg not long ago, and wow... im not a weak person, and it took me and a friend to get the old head out without touching my body panels.

same with the auto trans, took that dam thing out of a 7m on my own, without pulling the engine... i had it jacked really high up and took it out from the bottom... not reccomended...

I think because the 7M is prone to losing the head gasket if not done correctly, people "warn" against it. There is a right way and a wrong way, and its not something you can simply pull apart and slap together. The head has to be looked at closely (with the knowledge of what your looking for) to ensure its prepped correctly prior to reassembly. As well, the block can also need to be lapped depending on a whole lot of different things. So... if you want to do it as a novice.. no problem. Just make sure you find out exactly what your looking for before you start, or.. prepare to do it more than once.

I am 100% for novice mechanics (I have a friend that is a 25 year Master Mechanic (GM) and when I watch him work.. I know I am simply a novice.. lol)

Doing it is easy.. doing it right takes preparation..

oh and just a note.. you need MORE than the manual. The manual does not cover what people have found and a "tried and true" method has been developed. You can follow the manual, but there are little things people have found will make the headgasket last far longer and increase your chance at success. It just involves a little research.