Thanks for the information,I will give the shop you mention a ring.
I am a wee bit sceptical that we are just reducing string gauges here to reduce string tension.The MacDonald string calculator I used gave 164lbs for the gauges of Newton masterclass lights which I am using just now and 144 lbs for the low heritage set.If the mass and length of the string are fixed how can the string tension be any lower ?
One thing i did notice with the heritage set is that the tension on all the strings are all very even (23/24lbs).
I play a Avalon Gold A100 and a Taylor 314 so I will put a set on both and see how much differance it makes.
Thanks for the info on buying online Jimbo,I have used stringsdirect before very prompt and good prices.