Do you have a Walmart nearby rainbow? I find they sometimes have a good variety. Especially if you get there early enough in the season. Or Home Depot but they are pricey.
Rose of Sharon trees actually would be a good anchor plant on the ends. They usually don't grow too tall unless you let them. They have pretty flowers in a variety of colours. Good idea chico.
I was also thinking maybe Coral Bells. There are so many different varieties and colours now it's amazing. I have a light green one and a very dark burgundy. The flower isn't much but the leaves are spectacular! Just filling your bed with them would be eye catching. They are very hardy little plants that don't need any attention. They are also easy to find. The burgundy would look wonderful up against your house.
Just to show you the variety that is available now.
http://www.daytonnursery.com/encyclo...s/Heuchera.htm