The site where you can design your own moulds is www.mountainmolds.com I have quite a few of them, Dan makes them in either brass, iron or aluminium. It's a lot of fun designing what you want and seeing it draw on the screen, good molds as well, but you may have to wait a little while, but it will be worth it.

Re the Trailboss, the formula to use is to fill a case to the level of where the base of the bullet will be seated to with Trailboss, weigh it and repeat at least 5 times for the average, this amount is your MAXIMUM load, the recommended start is 70% of that amount.
It can be used in pretty much every calibre, although velocities can be a bit low, and it can show pressure signs very readily when you get near maximum.

DC