I carry:

2 Platy Hosers - 1L size with only one actual hose now.
1 Platy Tank - 4L size
1 Nalgene 32+ ounce canister made similarly to the Platypus bags. I put kool aid or gatorade mixes in this one and save the others for plain water.

I put one Hoser in an external side pouch of the pack, and put the water pump in the pouch on the other side of the pack.

I used to carry a Camelback 2L inside the pack - but found it easier having the 1L and water filter situated on the outside so I can get to them easily for refilling on the trail...