BIAB does seem like a good way to start, if you want to give it a try before building a tun. What I can't figure out is where you save an hour or more of time.
My second kettles sits inside the other, with my pitcher, salts, and thermometer inside that, so it doesn't take more time to move 1 than two. Juggling the lids can be a little problematic. Bring those upstairs, fill with water, throw in a little metabisulfate, and start heating the mash water. Then, my tun is down next to my grain bins. I grind right into the tun, then use the tun to carry the grain upstairs. When the water hits strike temperature, it goes into the tun.
At the end of the day, I carry the tun out to the compost pile, and turn it upside down. Rinse the tun a couple times with the hose (or the shower, in the winter) and it goes back down cellar. Wipe the kettle clean, everything goes back inside, and it all goes back down cellar.
I suppose I could streamline that to only 1 trip downstairs with 1 kettle and a bag, but that's only 2 minutes at the beginning and end of the day.