Curtis Brett got to your question before i could, good job Brett, glad you love them Curtis.
Scott, if you can find the S50's go for it, the S40's are great as well & the S20's can be used all around if you can't find the towers. The SC2 center compliments the S50's,S40's & S20's well, good luck in your search.
GabrielC try the spikes you will hear improvement in the bass, also good luck finding S50. I think AR stop making them.