[Tank]
Both are nice aquariums.
If I was to pick one for partitioning, it would be the Komoda.
Sorry, can't help you with the acrylic. Only place I know of is Bunnings.
[Species]
I'd recommend starting with CRS and CBS first, without mixing in another species.
[Substrate]
Benibachi soil is ok to use.
You also have a choice of Cal Labs Black Earth Premium. or ADA Aquasoil.
They will have different cycling requirements.
[Filter]
Both sizes will be fine. 2213 for the smaller 3ft and the 2217 for the bigger 4ft.
You could even get the 2215 impeller and use it in the 2213 - thus giving you similar flow rates as the 2215.
Definitely needs SS mesh intake protection. Mesh intakes will slow the water flow down, hence the suggestion with the 2215 impeller.
[Heater]
Heating a tank for shrimps is not a major problem. Any reasonably priced heater will do. A small one is enough. I used an Eheim jager 50W in my Mr Aqua 3ft bookshelf.
They can survive a Sydney winter without issue.
It's the cooling that will be your bigger issue. Sydney summer means you will eventually need to look into a Chiller.
If we get several hot days in a row, the shrimp will suffer, if the water temps rise above 28 for an extended period.
[Plants] & [Hardscape]
Your preference really. Mosses are popular for the ease and surface area for the shrimps to graze on. As well as it's low maintenance. You want to minimise having to stick your hands into the tank.
But an Iwagumi scape means the use of rocks and many iwagumi style rocks will alter water parameters. Best to avoid it now, or you will be constantly battling to control water parameters.
[Lights]
Pro Z is fine.
If you go with mainly mosses, then any light will do.
[RO unit]
Reverse Osmosis. Filters tap water and removes all the nasty minerals and additives and Chlorine and Chloramines, so that you can add in your own minerals to suit the shrimp's requirements.
Screw in one end to your tap, turn on the tap and output from one tube is clean pure water. Output from another tube is waste water for watering plants, or for washing clothes (do not drink).
Most of us purchase from FSA (Filter Systems Australia). 1300 888 008 ring them up and ask for an RO unit for aquariums.
[Other equipment]
TDS meter is a must have.
GH/KH kit is a must have.
Chiller as mentioned above. It might not be an immediate priority, especially if your house/room is cool. But maintaining a 23degC water temp gets very hard in summer.
[Other issues]
As with any aquarium, cycling is critical. Do it properly until no Ammonia or Nitrite is detectable.
Methods for cycling is the same for a fish tank. An existing, mature filter will help kick start the process.
DSM or WSM is up to you and what plants you want to keep.
But just remember my recommendation to avoid Iwagumi. Apart from the type of rocks used which alters Water Parameters, you need to stick your hands into the tank too much, too often (for trimming). It's not the best idea with shrimps. Tank stability is key to keeping shrimps healthy.
Sourcing shrimps and plants:
Sign up as a paid member of this forum, and the classifieds section will open up for you.
Apart from the cheaper prices forum members trade in, you will also get to participate in competitions that you might win free stuff.
Occasionally, generous members give free shrimps, plants or equipment away as well. And you will only see it in the classifieds section of the forum. Hence you NEED to be a member.
Keep asking questions along the way as you set up your tank.
@NoGi where is the link to purchase membership gone?
It's not easy finding it.