I wouldn't get too particular unless you are an experienced paddler and have a lot of well founded requirements.
Otherwise you need;
enough volume to support your weight.
enough keel length for good glide.
enough room under the foredeck to accomodate your shoe size.
a hull shape that fits your style of paddling i.e. rollable, dead stable, rockered, etc.
In the end, you have to make your own choices. If there is a plastic boat you admire you can use that as a starting point.

: Hi All,
: Just starting to really get interested in building a strip kayak. I was
: comtemplatin a canoe but now leaning toward kayak. There are tons of
: designs out there so I am looking for info on good designs for my first
: build. I am 6'2" and about 230 lbs. I will be using the kayak near
: shore in Lake Michigan as well as inland lakes and rivers. Eventually I am
: going to do kayaks for my wife and 2 daughters as well. I look forward to
: hearing from ya'll.