The Cicerone guide should cover all the walks, some are quite small but remember you can combine them to create a more bespoke walk that suits you. Try further South, around West Linton, places like Cauldstane Slap and the thieves road are worth a visit.
Another vote for the travel tap, only use it when wild camping. I carry an empty platypus and fill that up on the last available water supply. I then decant this into the travel tap for drinking/ cooking at the campsite.