Cyperus Helfiri doesn't mind current at all in my tank where it's right under of the spray bar. As long as it has established roots to hold it in place, it'll be fine. I haven't had it or seen it directly in a very strong current, but naturally it grows close to the banks of rivers anyway. Plus it can grow emersed if you want to include something like that in your setup.
Sent from my Galaxy Nexus using Tapatalk 2