Brake system upgrade? Old vs. New

I own a '53 pick-up with a 134 engine. My brakes delay whenever I try to slow down or stop. I think the master cylinder is shot, and it might also be wise to also replace the ancient brake lines. Should I purchase a new original master cylinder, or should I look into upgrading with a more modern aftermarket part? What brand and model of master cylinder should I purchase? And how do I replace the brake lines? Do they come as a kit that I can purchase for this truck?

Also, I really want to upgrade my parking break from the original design. Pulling that lever on the lower left side of the steering wheel can cause a hernia. And even if you miraculously succeed at pulling it as far as it can go, the parking brakes aren't likely to grab on any incline surface. Which is why I carry a block of wood to put behind the wheel.