When I used to fly, it was on very short lines. They were recommended by the guy who sold me my Matheson Midi, and I stuck with them thereafter. Now I return I see many of my problems learning were caused by just not having time to control the kite.
I asked Mark at JoE kites what lines I should consider if buying a Talon, and he replied, "No less than 75-80 feet [...] I personally fly on 100foot lines all the time (even UL). However, you really need to be used to that length to enjoy it."
What line would you recommend for vented kites in high wind, for std kites in std wind, and for UL kites in UL wind? I'm thinking particularly of the std and vented Talon, and the std and UL Benson DS.