Katie, I pulled my MC 15 plans for you. The distance from the bow to the front of the forward bulkhead is 57.25". The distance from the bow to the rear of the aft bulkhead is 116.75". The difference (59.50") less the thickness of the bulkheads, or 59", is the length of the cockpit. The cockpit coamings run from bulhead to bulkhead.
To build a kit you'll need a couple of saw horses, a drill and some small bits, linemen's pliers, 12-16 oz. hammer, diagonal wire cutter, clamps, a small block plane, 3/4" wood chisel, utility knife, putty knife, a Stanley surfform and a 25' tape measure.
For a drill I recommend a 9.6-12 volt cordless which can be used to drive screws. I have a servicible Ryobi 12 volt which came with two batteries, charger and case for under $75 at Home Depot. A dozen 2" "C" clamps will do for most of the work and if you get the cordless drill you can use sheetrock screws to hold things together while the resin cures. I've lashed decks down with bailing twine rather than drill holes that would have to be filled. A block plane can be had for $15 to $250. I recently found a nice old Stanley for $15 in a used tool shop. That kind of quality new is about $75 today. It's not worth spending too much on a plane for one job, but this is one tool that you get what you pay for. If you can find a good used plane, grab it and it will be a joy forever. As for the surfform the four inch block plane type is adequate. I also like the curved 2 inch model which can be pushed or pulled. It can get into places the others can't.

: Gini,

: Thanks for your input. Right now I think I've narrowed it down to a Mill
: Creek 15 or one of the Stillwater boats. I'm still trying to get some more
: advice about the Stillwaters. I would like your email, though, in case I
: go with the Mill Creek15. What tools did you need to have for this boat
: kit? You don't happen to know what the dimensions of the cockpit are, do
: you? the website specs don't say.