I had the exact same kit as you have + a 250mm lens and all of that fitted into a hadley (stacking the 80mm on top of the 50 or 150mm lens). Heavy indeed. When I trekked to Everest base camp and the Gokyo lakes in Nepal, I brought the 50mm, 150mm and 250mm lenses in a Lowepro Computrekker. Fine bag, not too heavy when empty. Everything fitted with plenty of room for an extra lens.

Good luck with your choice, Frank
www.frankbunnik.zenfolio.com