16L its a kinda small for the line of fish you want.
Endlers, maybe a Borneosucker (i think the tank its way too small)
For such a small tank i WOULD go with a Sponge filter.

 

I think you should check out the nano fish list on the forum! You could put green neons in or rasbora kubotai. Quick fish with very small mouths that wont bother your shirmp. Celestial pearl danios are also fantastic looking nano fish, but i believe they dont enjoy high flow as much.

Cleaning crew (bottom dwellers/ algae eaters) can be pigmy corydoras, otocinclus or maybe even salt and pepper corys, but they are slightly larger than the pigmys and they like to swim around more.

 

You have limited fish options with that 16L tank. I would say a couple of endlers is all you must stock. They are hardy little fish and do fine in small tanks.

 

tank is still cycling. i'm thinking about to stock it with. until the plants grow in to hinder the water flow a bit, the top half of the tank will have relatively high water flow (220L/hour for a 16L tank). would love some ideas.

aiming for neutral ph and will have shrimps as tank mates. preferably mid to top tank dwelling fish.

Endlers ..guppy's.
Guppy's love flow, at least mine do.
When I had the 55 they'd love to get blasted by the filter outlet. Like snow sledding.

Do NOT get a breeding pair...

AFAICT,with limited experience all fish need a rest area.

 

update:

i decided to rescape. i have now put the filter under the gravel with the outlet pointing up at the water surface. the opposite corner of the tank is now very calm from top to bottom. the bottom flow on the outlet side of the tank is also fairly calm. i might be going for some pygmy cory's after the plants have grown in a bit. may or may not be getting top dwellers depending on the NO3 level.