Jay,
I just did the brakes on my 1960 Imperial, which is pretty much the same as the 300F. I got the shoes, hoses and wheel cylinders from Rock Auto. I used Raybestos for the wheel cylinders and shoes. A friend used Centric wheel cylinders and had a lot of problems with them. The seals and bearings shouldn't be a problem.
Some of the hardware can be tricky but if your springs are good, reuse them. Make sure your brake supports are good and that the adjusters work. They can get stuck and then people round off the adjuster hex. They should be really stiff, but no so stiff that you can't turn them mounted on the car.
If you haven't pulled your rear drums yet, make sure you get a proper puller.
Nick