All those plants can grow to large for the 60cm rather fast, you may concider L. guinea, Rotala's sp. goias & pearl/mini, arthraxon, downoi, tonina's, erio's etc, hairgrass/parvula will grow to tall, Fissidens, HC or U. graminifolia make great forground in this small tank etc.
I have a tidy amount of Fissidens, but the amounts I would need would be staggering. Toninas are definitely an option. I always like the look of Belem, Lago, and Manaus. Never liked Fluviatilis (sp.?) very much.
Utricularia graminifolia is an option, and I've had some in the past, but the amounts I need would be excessive, and since it is so sought after now, I would have a difficult time in securing that amount. I'll probably go with HC, easier to find, and I have some on hand already.
Erio's are nice but once again, I run into the difficulty of securing them. Very rarely are they offered for sale. I wonder if Marc still has the E. "Guang Zhou".
How about Hygrophila 'araguaia' for some forground red.
I have tried that plant in the past. It's neat, to be sure. However, it doesn't seem to do a good job of providing total substrate coverage. It also grows rather slowly in comparison to most foreground plants. It could be a nice midground transition.
Ian, how large does your Sao Francisco Irecienu get? I always coveted that plant.......