XS do some nice big single consoles, they fit a 110l fuel tank in them. Not sure what you have fuel tank wise but 110l gives you good scope for cruising. Not sure if they supply them seperately and for what price but drop Lawrence an e-mail, he normally gets back to you pretty sharpish. Their consoles are glassed in, something to consider as they may not have the footprint to screw down (if thats how you plan to secure it).
I always thought for it's size, going by the pics, that your rib had a fair bit of space in the back. I'd considered a double when spec'ing mine but decided that in a 5.5m it just wasn't going to happen if I needed room to kit up, store cylinders etc. I finally ended up with sports console and 2 single jockeys behind, still takes alot of space up so I'm mulling over some kind of system to make the jockeys removable but haven't found an off the shelf system for this.
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