bamboo

If you only want one that gets to 8 feet, that limits your choice - most of them get a minimum of 10 feet, more usually 13 feet upwards. Have a look at Chimonobambusa marmorea (used to be called Arundinaria marmorea), which gets 8 feet by 3 feet. There is also a variegated version called (unsurprisingly) C. marmorea 'variegata'. There are 1 or 2 other bamboos which are much shorter, between 2 and 5 feet, but Chimonobambusa gets to the height you want. Although this one is a slow growing variety, I'd still be inclined to contain its roots to stop it spreading where you don't want it. This one won't like complete shade though, does need some sun. One variety that tolerates a lot of shade is the Sasas: S. palmata gets 10 feet high, S. veitchii gets 5 feet - the Sasas run though, so you will definitely need to contain the roots.

Fargesia rufa is a good clumper that also only reaches a max of 8ft. It's a relatively new introduction with reddish bracts in early summer.