I agree with what the others said. There are many here that have run arms similar to yours, and maybe even worse, and yet are still in one piece and working well.
But they're obviously compromised quite badly and will eventually fail. Most likely at the most inopportune moment. So yeah, new ones would be expedient.
Like was said though, you can use them still until you find better ones. Just don't wait too long. And if you can find some sooner, don't hesitate to put them on before you put this all back together with the new brakes.
Looks like the old original rubber c-bushings have had their day as well. Obviously that would need to be changed no matter which arms you're running.
Most of the vendors, including us, have pretty complete disc brake kits for the front. But if you want to keep it simple (i.e. cheaper!) you can simply do the disc swap without changing out the master OR adding a booster.
Drive it for a bit to see what you think. If you still need more power get the booster. If you need a more firm pedal get a larger bore master cylinder. If you need both, do both. You don't necessarily have to do it all at once.
In fact, you don't even need a disc/drum proportioning valve until you determine that you actually need one because your rear brakes lock up too soon. Even then, depending on the setup of your particular rig, you might end up with an adjustable one, rather than the factory style replacements.
All depends...
Good luck. On both fronts.
Paul
