For mid- to high-trail bikes, this set up would work well. But for low-trail bikes, then you're better off with the weight in front. The porteur racks were meant for lower trail bikes, which you probably already know. I like them without side rails, as it opens up the range of sizes I can carry, including sleeping bag and tent, bags of pet food plus my own groceries on top, bike stuff like wheels/rims, and so on. I've carried a lot of unanticipated loads this way, just because it was do-able. You can also just bungee a basket to the rack when you need to haul smaller loose items. Good luck with your build. It sounds like a fun one.