There are two kinds. There is fresh. Then there are products like Seachem Reef Phytoplankton or Bright well that come in bottles and are super concentrated. The concentrated bottles last up to 3 months after opening un-refrigerated and up to 6 months refrigerated. The fresh phyto lasts about 1 month. With fresh you usually have to dose a lot more.
There is debate on what is better. But both work. I just bought bright well, I used seachem at first, then fresh, and now I am going to try brightwell. I don't like having to pay shipping on fresh phyto as often as it is needed. I also don't like the large amounts I have to dose.
All that being said, each brand has a slightly different mix of phytoplankton, as their are TONS of species of the stuff. Some brands have different mixes. So dialing in what works best for you will vary. But most major brands will work.
If you want fresh I recommend Algaebarn. However unless your spending a good deal per shipment the shipping cost really adds up. If you want a concentrated solution most major brands offer one. I would get the 250ml bottles if you have a small tank. No point bulk buying a consumable. Don't buy more at one time than you will use in 3 months IMO, and keep it refrigerated if possible.
With your situation propagating pod.
I don't know if one or the other is better for pods. I have pods in my tank, and they get what they are served.
You might want to also get Zooplankton. Depending on species of pods, and what stage you plan to remove them.