Just to make the decision a little tougher...

:\I plan to install the vertical strips
: and then laminate an oak lip outside them.

Oak doesn't bend well; you might try bending a test strip to make sure one of your "good" strips doesn't break when you go around the sharp curve at the back of the coaming. You could consider steaming them. Clamp them in place one at a time at the middle of the back of the cockpit. Place a damp rag over the strip and steam it with a hot household iron. The strip will become much less rigid and you can iron the strip around the coaming riser. If you used hot melt glue to hold the riser strips together, make sure you don't get that riser too hot!!

: My question is, what distance should there be from the deck to the lip ? The
: book just says ( ... make sure the lip is equidistant from the deck all
: the way round... ) but not any recommendation as to the height.

You don't want any less than 1/2"--3/4" is a "nice" height.

: I plan on installing a lip which is 5/8" wide and 7/16" high.

5/8" is a pretty good width; 7/16" is a little tall. If you're fiberglassing the coaming, you don't need more than 1/4" of wood there. You really just need the lip under the wood to retain your sprayskirt bungie.

7/16" wide strips will be easier to keep aligned while you're bending them together around the riser. If it looks too tall to you after it's glued up, don't be afraid to sand off a good bit of the total height--it won't do you much good after the installation of the lip.

I plan to use 1/4" strips, but I'll install them one at a time to keep them aligned better.

Food for thought: commercial fiberglass coamings are less than 1/8" thick and they really hold the sprayskirt well.

Shawn