Would TIP120's suffice? I'm not familiar with the difference between the various TIP series.
This seems like an interesting means to limit current, I'll try it out on some less pricey LEDs first.
I do also have a bunch of mosfet's that I just ordered to try replacing the TIP120's I'm using elsewhere in this project. It would be incredibly convenient if I could use the same chips to drive these high-power LEDs as I'm using to drive lower powered 12V LED strips. I'm putting together a module that I'll be making a dozen or so of, if they're fully interchangeable that would be perfect.