You would only need one of the those kits, not all.
Two of the kits are not upgradeable, the microsquirt, and the DIYPNP.
http://www.diyautotune.com/catalog/diypnp-delphi-56pin-unassembled-kit-p-389.html
http://www.diyautotune.com/catalog/microsquirt-engine-management-system-30-wiring-harness-p-131.html
The DIYPNP may become upgradeable to the MS3, but it is not right now.
The other is the one is upgradeable to the MS3.
http://www.diyautotune.com/catalog/...le-efi-system-pcb30-kit-black-case-p-108.html
There is an unavoidable learning curve with the Megasquirt, and any other "stand alone" EFI system.
But the other systems out there are commonly sold to a consumer from a specialized vendor, and thus the transition from factory to aftermarket is easier(usually)
I.E. (hardware)things plug in, (software) a base tune, (support) very little things you have to figure out yourself, and so on.
This ease is directly proportional to the cost also.(those vendors have to stay in business, obviously)
The Megasquirt, is different, it is from an EFI collective of users, and developers. So it is a very flexable tool, but not one with out needed expertise.
No one makes a Plug and Play, Megasquirt for the TR. Yet. DIYautotune, was/is going to do an install write up on the GN platform, but it has not happened yet.
The nearest thing is the DIYPNP, 56 pin Delphi.(hardware)
I and many have basic tunes and configurations for the various version.(software)
First done on an MS1 by a member called
WopOnTour along time ago.
http://www.msextra.com/doc/ms1extra/MS_Extra_Ignition_Hardware_Manual.htm#c31
And there is a forum for any question anyone may have.(support)
http://www.msextra.com/forums/viewforum.php?f=125
I did my first one on an MS1 with a version 2.2 board quite awhile ago, so I have progressed thru the different levels, and I find the project of an MS3 install on the TR daunting.
So if you want a challenge it is there,or if you want to get it working ASAP it is there, if you want it to be easy, that depends on your comfort level with electronics, and cars.
I hope that this is not even more confusing the issue.