All urethane (sp?) hoses will harden and/or discolor and only the only hoses that will not harden are Tygon & OEM/Rubber (Pep Boys, NAPA, etc) hoses. Drawback is they do not look as sano.
If you compete or have a race ski I would pick up 25'+ of urethane hose so you can inspect the lines (and replace if its hard or discolored), otherwise go with Tygon or the black OEM/PEP/NAPA hose if you want it to look more sano.
What concerns are there about clogs, I mean if you have a new filter all lines after the filter should be clean? Right?