Thanks for the help guys, it is greatly appreciated.
I should be able to get away fine without materials analysis, since there are already industry standard materials for the parts I'm making, the drums are 7075-T6 aluminum, the hubs are 8620 steel, and the shafts are 4340 torsional steel. The valvebody I'm making will be 356-T6, hard anodized to prevent the steel valve from wearing on it.
I will talk to the CNC shop that will do some of the work, we're going to do a study so we can cost the project and figure out if we can do it with a decent profit margin. Not sure who we'll get to make the shaft, we MAY be able to buy one that already exists, since we're only changing the drum that shaft fits, not the location of the drum, and we can make the drum accept the shaft.
The one part is pretty complex, and will be fairly difficult to make work. I'm going to have to make the carrier out of aluminum if at all possible to get the weight down. But I will have to have a steel ring gear on the ID in the front, and it'll have to work with a splined steel shaft that locks into it in the back.