Willie's one-piece alloy unit is the cat's jammies, IMHO.
FWIW, I checked with McM and if you specify an
alloy or steel one-piece floorplate/triggerguard, they WILL inlet their stocks for that bottom metal, and you'll not be 'stuck' with ADL triggerguard woes. MPI will do the same.
Here (if all goes well!) is a picture of the guard.
... and a free bump! :-)
John