given the tank volume at 20(ish) litres, i'd go for a filter rated 250lph, giving you 10x turnover like this:
http://www.ebay.co.uk/itm/3-5W-250L...848710?hash=item3f59484746:g:SgAAAOSwMmBVu0os
for the lights you linked, it really depends on the plants you want to grow. There are so many factors including light height from substrate, the plants themselves, light duration etc. I'd be tempted to try it with two of them, and see how you get on; it's consistently been proven though that many plants can still grow in comparatively low lighting, so i'd always under light than over light if that makes sense.
for the black substrate and background, this will be good for showing off shrimp colours and plant colour, the only downside is that it can often look unnatural, compared to say brown substrates and black backgrounds, or blue backgrounds.
Also that's good dimensions for a scaping tank, depth front to back is quite often the most important factor in creating scale