In reply to illepo:
Decathlon do a decent Symbium access rucksack.. Not the lightest, but very comfy on. Full zip. £100 I have the 60+10 which is now no longer available. I also have a spare one in grey and blue if its of interest. (going cheap never used) Its specified as female fit, but apart from about a cm thinner shoulder padding thats about it... when Ive compared them.
They also do a cheaper one Forclaz Easifit 70L which has full zip front. Although not as sturdy so I'm told.
Salewa do a 60+10 Cammino with a front zip £95
The Osprey Kestrel 68 has a side pocket which allows full access to the inside from it. £120 ish
Mountain Warehouse to a cheapish (and not bad for them) rucksack Inca Extreme 65L which although not obvious from the pics on the website opens fully from the front as well.. for about £75
Post edited at 15:27