I know you said you have narrowed it down already to the Sirrus and Mira, but have you looked at the Skarab/Skimmer series? They have the hydration reservoir you are looking for and the magnetic tube holder. They also have 2 trekking pole loops and a Styrofoam back pad that is removable. I love this pack. The only down side is that they don't have hip belt pockets. I highly recommend the Skarab 22.