Frame- I used ortilieb on the bar, frame and seatpost bag, they were fantastic. Rear rack: never used one Dropper: I only build with one up. Never had issues, I use wolf tooth remotes Fork: bikepacking: rigid for all the mounts like an anything cage or equivalent, throw a jet boil or msr windburned on it, or a tarp etc. If you don’t need the space can’t go wrong with a mastodon, personally I use the lauf but that’s a different beast. Depending what/where u go consider a trailer and you don’t need anything and can set your bike up the way you want with less bulk. I have a burley nomad(Robert axle project) it’s crazy but very limited in trails. Way easier to pack.