Thanks man - the wide footprint does make a big difference when aquascaping. Really piling up the substrate at the back gives a really nice dimension to the composition.
sag. subulata is an excellent suggestion. I'm thinking a selection of Java ferns, Windelov, needle, and long leaf - Xmas moss on some really sculptural and large out of water driftwood, and then a carpet of glosso would look pretty good. Right at the back Aponogeton crispus (is this readily availible? Never seen it for sale) would look awesome with the flowers out of the water.