I've a pair of as new Stormline-Leda bib trousers for sale - Southern Seas range like these: http://www.stormline.co.nz/index_files/Page1267.htm . I bought them for a Scottish trip which didnt happen, and my lightweight waterproofs are good enough for what I do the rest of the time. They're made for full-on commercial fishing, not exactly the most breathable of trouser but should be fine if you're wearing a breathable top. However they should be as waterproof as the hull of your boat and slightly harder wearing
They're in medium - which fits me at 6 foot / 34in waist. I reckon you'd be fine at 5' 9" to 6'1" and 30 - 36" waist. Blue front and yellow back. I can send a picture if thats any help.
Looking for £40 posted (UK) and I'm at jonhill <at> live <dot> co <dot> uk or 0774 8111 436, and I'm based in London if you want to see/collect