The first thing that popped into the back of my head actually was some Vallisneria. It's a rather large plant if given room but I've found it really easy to control in shorter tanks, just needs some pruning every once in a while if you don't like the trailing on top of the water look. It also spreads well via runners and could create a nice "green curtain" look in the back and get rid of some of that glass background.
However I also like Slappy's idea of moving the wood/Abubias back and keeping the Bacopa carpet in front. Would be easier too.
However I also like Slappy's idea of moving the wood/Abubias back and keeping the Bacopa carpet in front. Would be easier too.