Shelly, I wouldn't purchase SED tubes at this point. I've learned, after seeing a tube of a SED quartet dying on my BH and causing some damages which needed specialist care, that they're not in production anymore. Some quartets or pairs being sold as matched, are just put-togethers from leftovers.
Considering I've had the chance to compare the SED and the JJs, I'd recommend you getting a good matched quad of JJ. Matched pairs also will do great, settings are completely separate for both channels.