Ditch the boga grip joni. I used one of those when I first started chasing carp, and I regret it. The boga is made for fish with hard mouths, and carp have one of the softest mouths out there. I think you would do less damage to a trout with the boga than you will to a carp. When i used the boga I repeatedly ripped holes in carps lips. It wasn't pretty...the boga is made for toothy critters, it just destroys the soft mouth of a carp.
Personally, I consider a net essential. I have a McLean net that folds in half and telescopes outward so I can handle a big fish solo without risking my rod at a bad angle. Plus, I can just weigh the fish in the net. I carry a small, light digital scale for that. It is a good system and much less dangerous for the fish than a boga. I think I sold mine on eBay after a few instances of nearly ripping off their mouth.
Check these out instead:
I have the "hinged ejector net" and I replaced the knotted mesh bag with a rubberized fish friendly mesh bag. Much safer for the fish, and it is bigger than you think. I netted a 25 lber and it fit (barely) the other day. That fish was 34 inches long, but I the head fit in and I was able to land it.