I recently tried Hilo strings and I like them, but the wonderful thing about ukulele strings is that they are not that expensive. Try some Hilos and if you don't like them you are only out $4.00!
in my opinion, white strings look better on a white uke than black
I guess another option is Risa fluorocarbons, which are also quite nice.
But the shipping from Germany might make it a bit costly compared to other options stated. www.ukulele.de
Fremonts are definitely loud (if loud is a priority of yours). But because of their high tension and extreme smoothness I find them uncomfortable to play.
The Blacklines and Orcas are both flourocarbon and should be brighter than nylon Hilos.
I have used both and like Blacklines and Orcas. Kala Reds may look cool or the new colored Aquilas.