I've been reading on how to properly obtain and own a SBR, but I still have a few questions (excuse the ignorance)

1.) If ordering a barrel from an online company do i ship it to my residence or a dealer? I already have a few Ar's which are all complete systems so I think I'd be safe keeping it at home. Then

2.) Since I'm going to be just swapping barrels in an upper do I fill out a forum 1 or forum 4?