I don't have a specific octave fuzz to recommend, but what are you using now, if anything? I have a COG Effects T65 that has its own effects loop that I can blend with anything. My entire chain is wired into it and I can use it to trigger multiple effects at once, both with and without the octave. It's a very versatile pedal! However, that Emma OKTO-NØJS is very unique, but considering it's a fuzz (a very good one) in parallel with an octave I can just about pull off those same tones with the T65 and whatever overdrive/fuzz I'd like.
I was using a digitech bass synth wah, with a idiot box blower box. Figured id see if I could knock it out in one pedal