The "cushion" the rod will generate is as much dictated by the action of the rod as it is by the length. You could have a flimsy 8 foot rod that provides a lot of cushion or a 15 foot rod that is stiff and provides none. Most people fish longer float rods in order to help mend the floating braid and/or keep the braid off the water entirely.

A 10' or 11' float rod is about right for most people although everyone has their preference. I use a Loomis 1263 and consider it a great float rod.
Seeing as how you want cushion, you're likely to start looking at "noodle rods" (long and super-soft). I'd avoid these rods as they lack the backbone to land fish quickly when/if you need to do so.
Good luck. If you are already breaking off big fish, you're basically doing it all right. Just bump the leader strength up a couple of notches.