unfortunately my legs have caused me issues with my kayaking life
(especially if I want to keep my shoes with me...) and therefore I want
to build myself a cheap canoe for fishing, canoeing & travel - just to
muck about in.

I can't afford to buy my own, but don't mind building my own now the
winter is here. I've seen a couple of cheap canoe plans

http://www.bigdamfish.net/ccanoeM.PDF seems pretty indepth and cheap -
but will it be stable for someone my size for the activities I want to
do, or should I be modfying the length?

Help :- ( preferably from someone who'll stop me from making an
expensive mistake!