Science Buddies: "Ask an Expert"

I'm trying to culture lactobacilli on solid medium agar plates (already prepared) for an experiment. If I'm not wrong, yogurt with fewer ingredients would be better to work with, but I'm conflicted on using Greek yogurt as it usually has a much higher CFU/g count and would have to be diluted further than yogurt with a lower concentration. So which types of yogurt or which specific brand would be the best for this purpose? Additionally, what would be the best way to dilute a sample, how far (with sterile fresh water, 1:10000?), and how would I best streak the plates for easier countability? Thanks. There are extensive sources online, but some of the language is difficult to understand, and sometimes information is not specific or is conflicting.

The experiment involves exposing these bacteria to microwave radiation, so I need some way to measure growth rates as well.