I know I would like to have some coral (not sure about the livliness of it) so I can get some anomeas (can't spell either). shrimps and some small fishies.
I'm confused here. You don't need corals to have shrimp or fish. I think maybe you're confusing live rock with coral, not sure.
This was my 20L after it was only set up for a couple of months.
The light on it is a 96watt coralife. I had A LOT more growth than in that pic after it was set up awhile. I really wish I woulda taken pics right before I moved everything. That's why I decided to move everything to a 50g, the tank became kind of constraining as far as aquascaping goes. I personally think a 20L is a pretty good size to start with though.
The live rock is all the filtration that was on it, about 25-30lbs (I was planning on a skimmer before I decided I was just gonna upgrade to a bigger tank...but the water parameters were good without one).
I really suggest you use distilled water or RO/DI water or else you will probably have algae problems. That's part of the reason you see a little bit of red cyano down in the sand, I started out using tapwater. After changing over to distilled that stuff went away.
I would also suggest koralia pumps over powerheads if you can afford them. I always had problems with powerheads falling off and then they suck in sand and stop running, or blow your sand everywhere at the least. They also have kind of hard flow so it makes it a little difficult to position corals where they're not just get hammered.
You won't be able to have many fish in a 20L but you can definately have a lot of little soft corals, mushrooms, polyps...stuff like that. I wouldn't personally do anemones, they can be touchy and they also produce quite a bit of waste.
Anyway, hope that gives you just a little inspiration for your own tank. Good luck