I am a 55 year old top shape 143 pounds 5,8' wanting to buy a Look bicycle. I run 2 000 Kilometers per year (or 1 200 miles) and I would like to know if a 585 would be too stiff for me. Would a 565 or a 555 be better for me? I want an efficient but comfortable bicycle and I keep my bikes for many years. Thanks for any advice.