I have a set of Regatta Pack-a-away waterproofs, made with breathable Isolite 5000 , they can be rolled up to almost nothing and even have their own stuff-sack to carry them in. They work really well, espcially if worn with a base layer with good wicking properties. You can stuff them into a backpack or large bum bag to have them handy.

For my feet I wear walkers gaitors (or spats I think in the US?), mne are goretex and have never let me down as yet. I also have a good pair of waterproof shoes.

Of course, with any waterproof and exertion you are going to sweat, but if the sweat is constantly being being wicked away and evaporated it helps, rather than have it just gather within the clothing.

Regatta Packaway II