So I was also looking at the mTDI option (mechanical TDI for simplicity) for less boost required (less stress on engine components) to make similar power as above. Also, the TDI's, with much lower compression ratios vs the older IDI's as well as by the design/nature, is a better cold starter as frigid winter temperatures get below 15 degrees F or so...
TDI's also have no pre-chamber cup steel inserts in the aluminum heads, so one less thing that could go wrong there.
These kind of power figures really are warranting a Toyota R150/R151 trans...or at least a W56. I'm really shooting for the R150/R151F for the best of the bunch, longest lasting.
Also I have started considering a VW ALH model 1.9TDI, as they are far more plentiful in the wrecking yards these days, and can be had for significantly cheaper than a 1Z/AHU 1st gen TDI, or a 1.9TD-IDI "AAZ" Canadian import engine. Also, these are the 1st of the newer generation of the TDI engines, and have metro alloys / metallurgy than the older engines even, and we'll run significantly longer before the cylinder bores need overbored. They also no longer have the intermediate shaft set up with extra seals and bearings to wear out, to turn the oil pump shaft water pump etc. Less chances for leaks!
This is also I believe the last of the TDI engines that uses a Bosch VE injection pump. It is electronically controlled, but is not too far off from the mechanical versions of this pump, and parts from this can be adapted into other model Bosch VE pumps to make it a mechanical TDI.
The downsides are that no engine mounts or other accessory bracketry or tech support are available when swapping this into a samurai other than the bellhousing adapter. Custom mounts can be fabbed. It will likely get the engine and trans clocked 15 degrees to the passenger side for slightly more oil pan clearance to the front axle 3rd member, which will also help with floor to transfer case clearancing, as well as transfer case output heights.