So finally posting an update, but it works!
For quick reference, I opted to use the motor from an 06 Tacoma since that's what I could find on FB Marketplace for a good deal, but everything written in this thread beforehand is still applicable. The only other difference with the Tacoma motor that I noticed was that the oil filter housing has a cooling circuit that runs to the thermostat housing and back. Otherwise, same changes are required as detailed above.
The tensioner behavior ended up being a non-issue; a service tech at the dealership said that's just how those oil-pressure supported tensioners behave in the absence of oil pressure. I spun the crank over ~200 times in order to make the timing marks all line back up 3 times without issue before I put it together.
Got everything put together and went for a first start, then it ran like absolute crap and gave me tons of misfire codes and other codes. Crap. After swapping around coil packs and spark plugs, checking harness voltages, and trying everything I knew, I gave up and towed it up to Toyota. Turns out I had left a chipped piece of the old VVT solenoid in the valley of the motor, and it got wedged between the lower intake manifold and the heads. So, when I torqued the intake manifold down with that piece in there, it cracked the manifold and created a massive vacuum leak directly into the valves....pay attention kids and clean up your work surface properly.
Swapped the intake manifold from my old motor over, and she ran like a champ. Had 2 leaking hoses at the thermostat housing that I had to replace, and then no issues so far after 200 miles of driving on it! Going to Windrock this coming weekend for it's first wheeling trip in almost a year.
