Interesting, I have been running that engine for 28 years and never seen a documented issue with head bolts. For 14 years I spun one past 8,000 every time it was on a track. I have over 280000 miles driving Starions, most all of that was with higher than stock boost. I have just over 100,000 miles on the turbo Montero conversion and never seen an issue with Mitsubishi head bolts and you are putting together a stock engine and need them. Interesting. You have much more money to spend than most of us then.
By the way, the MLS gaskets are riveted together and are located by the dowels that locate the head.