I was going to hold my tongue here, but you did post up asking for opinions

. Since tone and intent are often lost or misinterpreted on forums, please know that I am genuinely trying to be constructive and share experience here.
From the perspective of someone who has done a number of builds over the last 15 years, I can tell you that as I read this thread, 3 things come to mind:
A) This is going to cost you 3 X what you think it will
B) This will take you 3X longer to complete than you think it will
C) You are going to be highly disappointed with the results
Allow me to elaborate. First off, the 2L diesel is about the worst motor Toyota ever put their name on. It's a dog with fleas that can't get out of it's own way. It crates NO power, has universal overheating and head cracking issues and will get nowhere near 35 MPG as stated earlier. As for the FJ60 option, while incredibly durable and far more reliable than the 2L, the 2F is not much better in the power department as I know you are already aware.
Second, swapping a Chinook onto a Hilux, then performing a SAS / 4wd conversion is a metric S-ton of work....REALLY expensive if you are not doing the work yourself and you want it done right. If you are getting the work done cheap, the results will be what you paid for.
Lastly...every wood constructed camper made will leak water at some point. I played with the idea of mounting a flat-bed 4 wheel camper on my
last build, but that lack of durability steered me away from it.
Take it from someone who has pissed away far too much of his life savings in search of 4x4 camper nirvana. Start with asking yourself a few questions:
1) Where do you want to take this rig?
2) How many people are you taking and what essential gear must you fit?
3) How capable must it be to get to those places? (i.e....if your goal is just to access forest service roads, then do you need a super capable 4x4?)
4) How important is power and the ability to maintain speed climbing a long mountain grade?
5) How important are basic comforts like AC, Cruise, a roomy interior?
6) What are your must haves related to Solid axle vs. IFS, 12 vs. 24 Volt, RHD vs. LHD, Gas vs. Diesel...they all have their pros & cons
7) And the most important question....what is your budget??
I asked myself all these questions after 15+ years of buying, building and wheeling different platforms and ended up with the rig you see below. That said, if I knew 15 years ago what I know now, I'd have saved more money than I care to think about. Like you, I wanted all the comforts of a motorhome (cooking, showering, fridge, freezer, toilet, shade, comfortable bed etc.) but I wanted it to be equally at home on the long open road as it was on the toughest trails in the country. I sort of feel like I have achieved that this time around.
If I were you, I'd sell the Chinook and look for a platform that is 80% + of what you are looking for in a finished project. If the FJ60 and the 2L Hilux need to go in order to fund that, so be it...you will end up far further in the end I promise you.
Again...please take this post for what it's worth...not trying to be a dick or piss on your parade, just trying to pass along advice based on experience and have you put some sober thought into this decision before you get too far down the path. Best of luck with whatever you do!