The Exos 58 has two mesh pockets, one on each side, that hold pretty much any 1 liter bottle (hard-side Nalgene, collapsible Platypus, sport bottles, etc.) I hope I haven't misunderstood your question - I'm not sure why you think "most backpacks today don't have a side water bottle pocket." Offhand, I can't think of one that doesn't.

You need to be aware, also, that the Exos is an ultralight pack - for me (at 67), it starts getting uncomfortable with a 25 pound load; below that, they are a really comfortable series of pack. If your load, including food and water for however long you'll be out (or between resupply), is much above 25, you might want to look at different packs. In particular, I prefer the Kestrel 48; above 30 pounds, and the Atmos AG series might be perfect. The Volt 60 might also be a good choice for heavy and bulky loads. The Kestrel is a three and a half pound pack; the Atmos and Volt are just over 4 pounds.

The Deuter packs (especially the ACT Lite and ACT Zero series) are good load carriers, too.

Good luck. I still miss my Camp Trails Wilderness packs (I had both the external and internal versions); they had great water bottle pockets, sized perfectly for Nalgenes.