Dakine Photo Mission 2007 or 2009
I've got a 2009 black one, yeah its maybe a bit bigger than it needs to be (its a bag inside a bag), but its damn comfy, carries two lensed up bodies + flash + stuff + pouch for cards, batteries films + a proper water bottle holder OUTSIDE of your kit + can ACTUALLY hold a proper tripod (slik pro400/440dx similar to a Manfrotto 190x, and 2.5kgs) it can hold a tripod so well you can run full tilt with it, and the tripod not clatter around.
With MOST of the lowepro bags that say they can carry a tripod, the max is really a manfrotto modo/718 kind of sized pod (<1kg) and even then, its usually on elasticated bungees which stretch and allow your pod to whack you in the back of the head, the lower back, the back of the legs or fall off all together. bit pants really when you can be spending upto £140 on one of them.
the Dakine goes for about £60-80 new posted. got mine new posted for £59

Its made from the usual cordura type fabrics and robust zips & clips, the back padding is brilliant, the sternum & waist straps are robust, it has a waterproof cover, though not needed unless its amazon type rain. Only thing I don't like about it is the relative bulk considering the amount of kit you can get in it, and the zips 'jangle' like mad, I put some black electrical tape on them to keep them quiet.