OK, Tom beat me to it!
You may have lucked out as if the boat already had theK&B in it then it should have a 1/4" drive installed so that'll save you a bunch right there.
I've used a lot of the Zippkits radio boxes, they're light and fit really well betweeen the 5" rails. I went and got all fancy and used his billet aluminum servo mounts, they make installing and removing servo's a piece of cake. Joe should have everything that you'd need for the conversion and then some. Shipping is always fast. Most of the time his wife Stasia takes the phone orders, she's a sweetheart.
I'm trying to upload a shot, this site isn't letting me do it right now. I'll try again later.