I would definitely check out the airline you are going to fly. The measurements for carry-ons change for 1 to the next. Also, the weight limits and charges change.
I fly to Alaska to hunt on a regular basis. If you can fly Alaska Air I would advise it! I carry on my Kifaru EMR2 (which is huge loaded) and it fits in the overhead baggage of their planes. I compress the EMR2 so it's close to the max measurements. Alaska Air also allows an extra carry on "bag". I carry on my EMR2 plus a giant camera case loaded with my spotter, cameras, camcorder, etc. It's a royal pain in the rear but I usually carry on around 70 lbs of gear this way. I get a lot of looks in the airport!
Another thing I've learned is to gut the foam in my giant rifle case that is on rollers. I fill the rifle case with clothes, fishing rods, trekking poles, etc. until it reaches the maximum wt. It's nice having a rifle case on rollers so I can place other baggage on top of it for hauling through the airport.