Congratulations on deciding to keep cherry shrimp, they are colourful additctive little critters. A word of caution with using a smaller sized tank with intended breeding colonies of cherry shrimp. Even though cherry shrimp are generally small their numbers do build up and with the increased numbers their bioload can become quite high. I have also noticed with my own tanks, where cherry shrimp where given plenty of space in say a 4ft fish tank (even with fish) and a 1000L pond the cherry shrimp seemed to get to greater sizes than those kept and bred in say a 20L tank with no potential predation by fish. Although I did end up with some dragonfly nymphs that almost completely wiped out the chocolate colony I was trying to establish. Now all my shrimp are kept either with fish that will predate on things like dragonfly nymphs or in closed lid tanks. If a tank is kept indoors there is less chance of dragonflys laying eggs in the tank, but hitchhikers have been known to come in via weeds/ plantlife. Speaking of which plantlife can also at times harbour hydra which you do not want any where near your shrimp, and certain snails. Now snails generally are not an issue for shrimp, its not like the snails are going to attack and eat the shrimp, BUT the snails particularly pest species can breed into outragous numbers, swarming the shrimp food preventing the shrimp from getting their food, eating all the bilfilm which shrimp will also eat and using valuable minerals that the shrimp need for thier shell production to assist in their roughly monthly sheddings. If you decide to treat any plants with chemicals prior to adding them to the tank, just keep in mind that many chemicals designed to kill pests will also kill shrimp.
I would not use your Amano shrimp to help cycle the tank, Amano shrimp can be very susceptable the nitrites and nitrates and the biofilm they often feed on along with algeas just will not be present in a cycling tank. Also Amano shrimp need very specialised breeding techniques as their young have larval platonic stages that range from being born in fresh water, moving out via tidal flows into either full salt or brackish, feeding on special floating algeas and then gradually making their way back into fresh water as they mature. Breeding and raising Amano shrimp is not for the feint hearted and is almost the holy grail in shrimp keeping.
For substrate I would use a sand substrate simply because if you need to remove the shrimp at some point down the track it is much easier to catch them. I have seen newborn and young cherry shrimp duck down through the cracks and gaps of gravel, making it impossible to catch them. Many a time I have removed all the tanks gravel, had only a couple of cm's of water left in the tank and its full of muck only to find a few straggler baby shrimp still wondering around. I have even found shrimp that where hiding in the gravel have gone for a trip to where ever the gravel went. If you find them before drying out, you can just put them back in water but trust me small shrimp are not easy to pick up with out damaging them.
Depending on the gH and pH of your water you may not need to use specialised shrimp soils, but I believe a mineral ball wont hurt with the general overall health of your shrimp.
You would still need to do weekly water changes on the tank, siphoning/ vacuuming the bottom of the tank and its substrate will probably be a no-no because you will probably end up sucking up shrimplets by accident. Depending on the needs of the tank you could do 25% once a week or 50%. I find with a smaller tank, its very easy to accidently do closer to 70% changes by accident if you get ingrossed in cleaning the filter in the out going tank water.
Cycling the tank will depend on if you use any existing media (be it filter media, gravel or logs) from a previously established tank. Water temp can also affect the speed of the cycle, too hot or too cold can really slow things down.
