I think that some red swords would look nice. I do agree that you do need some sort of different leaf shape and some reds and pinks in it.
Some rotala indica/rotundifolia would look pretty neat in the tank somewhere, as long as you kept it trimmed and prevented bushyness from overtaking it, it would look nice, and get a real pretty pink towards the top of the tank.
Maybe some type of ludwegia? Repens would prolly be the best option until you know it will do well in your tank. I had some in my 10 gallon, but I had 30 watts of light. It also did well for me in my 29 with 2.43 wpg's...haha
Perhaps red or purple cobomba? I've never had it so I'm not sure how well it would do, but the green seems to do well enough in lower light tanks.
I would throw some C. retrospiralis in the right corner. The stuff we have for sale at the lfs I work at has some reddish color coming into it, and it would do well in your lighting. The only thing is that it has a sort of grassy look to it. But it would still look nice.
I think the best option would be some type of red sword. Just as long as you keep them trimmed, you shouldn't have too much of a problem.
65 gallon low tech planted