I ended up buying a complete chassis with an actual m2 IFS that has been professionally cut and welded onto the frame. The guy that did it has an excelent reputation so I'm not worried about the workmanship, just details like proper sizing and fit. The FE was welded on a bit forward due to the new suspension being much lower than before.

Is there anything I should be aware of, since this was not a "kit" specifically made for the truck?

I got the whole thing, complete with disks and a rebuilt rear end for only $400. The chassis belonged to a truck that was partially built when parked next to a huge stack of hay. The hay caught on fire and the truck was burned bad. The owner gave the truck back to the guy that built it because of debt, then I bought the chassis from him just to "get it out of the yard." Hopefully it was a wise choice.