I use sunlight for all my emersed bins. As long as you get some direct sun it should work fine. I get about 6 hrs on my bins and they do great (DHG,Microswords, Syn'belem', etc).
I'm doing the same for a dry start tank once my Aquasoil arrives. Once its grown in, i'll move it, add water and a light.
Crypts do fine emersed but the leaves look different than submersed growth....and they dont seem to grow any faster for me emersed.