Most dealers are annoying about custom orders. But it can be done with a dealer who is patient enough, or has the staff to do it. Works pretty much the same way as any car coming that is allocated to a dealer before its built. I believe it will take (normally) 2-3 months. Somewhere around there.
I wanted a '24 TRD Off Road with the premium package. Wow, talk about a difficult search! It took me 3 months but I finally found one in Tennessee. (I live in Texas) I picked mine up at Toyota of Coolsprings just south of Nashville. The salesman told me a lot of their customers in that area prefer the long bed. Only negative of my purchase was that I couldn't get it in Icecap.