>I have been thinking of a uni-device pfd-harness-camelback
>for distance races and may sew one up as soon as I can get
>all the parts together.

This might bring you into conflict (if you care about such
things) with ISAF rule 43.1(a)"competitors shall not
wear ... equipment for the purpose of increasing their
weight". I do not know how strictly this is handled but a
camelpack might definitely be interpreted as increasing
your weight.

Ceitzi