Tug Guy, here is a good site for info on the build.
http://www.rktman.com/rlh/boothbay/steps/steps.html
Try and put everything on that you will be using and then set up your ballast. AS best you can at least.
I placed small containers on the deck and filled them with shot until close. Then I just added to the shot to the hull until i was happy with the ballast. It did not take a lot of shot. I used some old lead shotgun shells and cut them open. It was cheaper and easier than trying to buy a few ozs of lead shot.
My main batteries and in the front cabin either side of the motor next to the hull. I just used the recommended batterys and motor by mid west in their instructions.
Just remember the lower the weight is in the boat the better the stability.
Kevin