Caravaneer's Challenge is cleared! Although it took a few rough tries and I carted twice, it wasn't as hard as I thought it would be. I was using Auberon the Lagiacrus set (Awaken, Focus, Weakness Exploit) with CritDraw and ResTremor (for Rajang) slotted in.
I think there's a quest still hanging around, but otherwise done with offline high rank until I get access to G quests. I think I'm pretty close to doing that (rank 7).
For posterity (lol), here's what I made for high rank (some starting at low rank):
Weapons: Dark of Night (Kut-Ku>Narga GS), Grimmig Cat Katze (paralyzing felyne SA), L'Oppresseur (Gore Charge Blade), Shell Castanet (Hermitaur Hunting Horn), Auberon (the Azure 'Los GS with awakened element), Odyssey Blade (Ludroth SnS)
Armor: Nerscylla S, Skull/Velociprey/Tigrex/Chrome/Tetsucabra (popular Sharp+1, Atk XL build), Lagiacrus (become a little obsessed with Awaken weapons at this point)
I ended up building a lot of weapons, but I got good mileage out of them. Haven't touched either lances and I'm not used I want to play a ranged class, think I'll correct at least the former. For G-rank, I think I'll explore some of the crazy shit you can do with SnS, speed setup, and evasion+2.