cjwuna,
have a look at the Shrimp Tank Setup subforum for a view of what substrate people use.
But in short there are Cal Aqua Labs Black Earth Premium, ADA Aquasoil, Benibachi Fulvic Grain that is available in Aus which is highly recommended by many shrimpkeepers for Caridina shrimp (CRS, CBS, TB). I like CAL Black Earth Premium, since I find it less dirty (unwanted debris) than ADA or Benibachi. CAL BEP also cycles faster than ADA, and does not release as much ammonia like ADA. When moving plants around, there is less "stuff" kicked up to cloud the water. ADA seems to kick up a huge amount of debris that clouds the water. Benibachi seems to fall in between CAL BEP and ADA in every aspect (My observations only).
You can't go wrong choosing one of these 3 substrates. Just make sure you cycle them properly, especially ADA substrates, they will take a lot longer.
The lower premium products are Ista, Mr Aqua, Up Aqua etc. These are cheaper and don't buffer for as long as the first 3 mentioned above. As a result they can also be used for Neocaridina shrimp.
For Neocaridina shrimp (cherries, rilli, etc), you can use any inert gravel or substrate like pebbles, sand, or what I do sometimes based on availability - I use old spent plant substrate, ie my old ADA or benibachi substrate. I seem to never throw out old substrate.
Our sponsor Tech Den also sell Shirakura Bee Sand substrate. It's not a new product, but it's new to Aus. I have not used it, but it seems to be ok from what I have read about it. Very similar to CAL BEP. Good pH control at 6.5, buffers a long time, does not cloud the water at startup. Cycles quickly.
SKF sponsor Age of Aquariums also stock a lot of plant/shrimp substrates. They also have Fluval shrimp substrates, which currently would be ranked in the between the premium substrates and inert gravels. Good for Neocaridina or Tiger shrimps.
You can also find other substrates like Seachem Flourite, Ecocomplete or Dupla Ground, that are generally inert which is great for Neocaridina shrimp. They might contain some minerals that plants can use but generally do not buffer the water to maintain the pH, KH, GH for Caridina shrimps. But why pay more for such susbtrate when you can get cheaper inert gravels.
Hope this helps you choose a substrate.