I tried dozens of companion knives for my DFLE and think the HairyCarry is the best so far. The Yk's and Mutts are far to thick for the kind of delicate work you would want for a companion knife and you have a DF for the big stuff. The Muppy would be a good choice if you want to stay in species or an SS4 although i find the mudder handles to big for piggyback sheaths they would work well with a separate sheath.