before you go down the infinite, bottomless rabbit holes to follow, a word of caution. 4x4 is much bigger than you think, especially considering your circumstances and the ramifications. watering alone is a whole thing. don’t get married to the 4x4 until you see the tent erected in place, and have a clear idea of the cost of all the hard parts you’ll need up front, plus a bunch of stuff you don’t know about yet, plus the soon-to-be very legitimate running costs.
you almost can’t go too small at first. too big is much worse.
a clean, dialed-in cabinet is a beautiful thing, and super underrated. a few years ago, I heard about a guy in NY making full-custom boutique grow boxes that look like posh furniture. not sure if he’s still making them, but that would be super nice to have.
in general, it wouldn’t hurt to dig through the archives of guys like Dr. Bud, blynx, and @Mr.Sparkle
@vernal kinda nailed it here.
i don’t mean to be a downer, just trying to help you avoid issues i’ve faced in similar circumstances in the past. 