Good hiking pack for a mamiya 645 kit?

I'm starting with a 645 and 80mm lens but will eventually have a 55mm and 150mm lens. I'm looking for a backpack that will suit this kit, be fairly light weight, and distributing the weight to my hips vs. my back would be a plus. Would like to grab something cheap off of ebay. Any suggestions? Thanks

I have a Mamiya 645 with similar lens 4 backs, a spot meter and always carry a 35mm with a couple of lens in addition to a load of film and get this lot comfortably into a Domke OutBack. It is very comfortable and not too heavy.

If fit my Mamiya 645, 35mm, 80 mm lenses and Minolta X-700 with 24mm and 135mm lenses with my spotmeter, some film and a pile of filters into my Lowepro Mini Trekker. It also has a compartment for travel documents etc, so very handy to use when you travel. It is fairly lightweight and very comfortable to carry on your back.

There is only one downside: it is not waterproof.

Anne Marieke