Generally, the simplest option is to use a factory clutch/brake pedal assembly for your year/model as a bolt-in. The next options in order of cost and labor are grafting a pedal to your assembly, modifying one from a different model to fit yours, and fabbing the assembly from scratch.
Note that if you find an original assembly to use, try to get one that has the same brake option you have (power or manual brakes). If not, you can still use the assembly, but it may require moving the brake pin to the proper location for your type, as some models use a higher location (greater leverage) for manual brakes than power. The clutch rod pin is usually the same location for either brake type.
David