Not to be the party pooper but before you start experimenting with sourdough starters, yogurts, probiotics, milk kefir, beer, etc., you should be able to make a satisfactory pizza crust with commerical yeast. If you aren't happy with your pizza crust with commercial yeast (ADY, IDY, CY), I'm not sure adding more ingredients will improve it. Become familiar and proficient with the basics, then expand your knowledge. If you are already past the basics, then by all means experiment away. After 3 years of constant experimenting, I have just barely begun to understand the basics of making a good pizza crust that meets my standards and expectations.