Personally, …
I’m just getting into rowing and loving it. Even looking to sell a couple of canoes and a kayak to finance a rowboat. There’s really a lot out there inclduing decked ones such as the Angus Boats already posted
Since you’re a builder you might consider this one; http://www.clcboats.com/shop/boats/rowboats/expedition-wherry.html.
If you don’t like, I’ll trade you a kayak 
this is moving from a want
To need to see and operate boat.
http://www.clcboats.com/shop/boats/wooden-sailboat-kits/clc-faering-cruiser.html
I’ve looked at that one
Beyond my building skills, and I would think rowing wouldn’t be easy; 650 lbs is a lot of boat.
However, I’m with you, I’d love to see it, and try it out.
Calm kayak?
I would guess you are talking about something with very secure stability, not a boat with whom you plan to have an emotional relationship.
I have to repeat my suggestion that you focus on skills sooner. Stability the way most newer paddlers mean it can almost be the enemy of fun as your skills come on. And flat water stability is not the same as what will keep you safe in more open water, though the difference is less apparent in a wider rowing boat than in a 22 inch wide kayak.
kayaks
If you’re looking for stitch & glue, I like the Pygmy kayaks and the CLC Shearwater line. If you’re interested in strip-built, Guillemot, One Ocean Kayaks, Redfish Kayaks, Bear Mountain Boats, Laughing Loon, Shearwater Boats are good places to look.
There’s a good kayak building forum at http://www.kayakforum.com/cgi-bin/Building/index.cgi
Remember that a kayak should fit your size and weight.
I’ve rowed fixed and sliding-seat boats. Seaworthiness has a lot do do with operator skill and judgement. Fishermen used to work the Atlantic in open boats, but they grew up on the water and had far more sea sense than most of us ever will.
Rowing a boat designed for rowing – as opposed to a runabout without a motor – can be a real pleasure. But I suspect that for equal seat time, most folks would be better off in a sea kayak in rough conditions.
An opposing view, from folks who make some great boats: http://www.adirondack-guide-boat.com/category/our-rough-water-department