Please, do some searching, good info was said above already.
But to be more specific about which HG size you need. You have to know how much material was taken off the block and head in total. The stock height of the head and block in on SM somewhere the number aren't 100% in my head so I won't put them. Which is part of why you should search to make sure. Use stock heights, measure the height of block and head now with something accurate. Subtract that from the original. The difference, i.e. 2.0mm will be the thickness you need to get.
The bore will be 83mm stock...if you've bored out aka made the diameter bigger in the combustion chamber then you need a bigger bore headgasket. Every 40 thousandths of an inch (0.040") is 1mm bigger. If you bored it 80 over (0.080) then you need a 85mm bore headgasket at least.
Basically, HKS is the standard for MHG, a large reason is because they perform well and Greddy is less available. Well that's two reasons.
If you aren't going to be able to send the block to a machine shop for the surface to be smoothed to the spec needed for a MHG, I believe 50ra or less, Then you get some help from someone who will know how to inspect it in the car or or sand it down as flat as possible. Get the head checked and done.
Use a cometic if you aren't going to be able to take the block out as mentioned it will help seal better if the surfaces aren't perfect.
I guess I saved yuo some searching. But you should still read around and get it right and make it the last time. good luck.
