Well dun go for 1-n as its not much liked especially the mechanics thinks its not good...
Go for 1-C and avoid turbo
But its better u get ur Mitsu engine overhaul bcoz changing a engine and placin a 1-c or 1-n will need alteration alots of parts will be replaced its better in my view to rebuild this engine which is workin in the current setup
BTW u have a good mechanic ?