What are the rest of the parameters on your tank? Lighting, CO2, fertilizers, etc... It will be dificult to make any suggestions without that info. If you are thinking higher light, CO2 and ferts then stem plants like Ludwigia sp, rotala sp and others will grow as tall as you let them. There are also some really nice tanks in the aquascaping forum that are biotopes for SA cichlids with very few plants and using manzanita driftwood, almond leaves for black water, etc...