The easy answer is, it depends... :-) The Toyota box (if you can find one) has a side-output like the original, mounts in the same (or close) location and will run the stock steering with few mods. From what I understand, they stand up well to off-road use, and should be reliable. It may require a new pitman arm and a modified drag link due to spline count, mounting height, etc.

The chevy box is a bottom-output designed for cross-link steering (uses two tie rods and a center rod, sorta like R+P, and uses the box at one end of the center rod and an idler arm at the other to hold it all to the truck). As a result, they are designed to mount forward on the frame rail (have to move the left shock mount) and require a different pitman arm, drag link and steering arm to run the steering.

Kits are available for both, including boxes for both. I see them in ads in the mags for about $699.

Good luck with your decision.

... I wonder if anyone has tried flipping the steering arms on a straight-axle truck and using a full cross-link installation?....

Current fleet (subject to change w/o notice)
\'49 GMC 3/4-Ton , 60 Austin Healey Frog-eye Sprite (some assembly required), 2011 Dodge Avenger, 2015 Jeep Cherokee. No, they don't all run.
My other ride is a (B737)no, (B767)no, A320.... Update... was Embraer E190, now Boeing B787.

Knowledge is a wonderful thing, but ignorance means you don't know you can't do something.