Have you already purchased the new sac? If not, I would recommend
Fly High's Pro X Series Tube Sac You could then use 2 Fly High W737 Fittings to connect your hoses.
If you have already purchased the new bag, you should be able to put a hose clamp on to ensure a good seal between the barbs as the hose, just make sure you don't tighten to the point of collapse.