Gary Dodd has an excellent and flexible 6v/12v tube buffer.  The DIY kit starts at $349.   http://doddaudio.com/diy.aspx   Email Gary directly for deals on fully built-up kits in boxes, etc.  He's a great guy to work with.

Guys, I'm really flattered by the kind words.  I need to pay more attention to this growing community.  Thank you so much for including us!