With a adapter plate you will use the 1UZ auto bell housing, a modified flywheel (3SGTE?), and any clutch set up for the R154 (disk and plate). You will have to provide access in the bell housing to install the clutch. Then you will need to do something about the slave cylinder, since it will be internal. The Howe throwout bearing is common (I have it in mine, but I also have had a failure), but Quartermaster makes one that is superior to it, but the cost is a little more as well. Get in touch with the web master at 1UZSUPRA.com, he has a R154 in his 1UZ car and will be able to offer more details.
Personally if I were to buy another adapter for the 1UZ I would go with a T-56, I see them more often for sale vs a R154.
Good luck!