To answer your original question...try Mystere CA11 or CA21 preamps. The CA11 uses a SRPP (Series Regulated Push-Pull) circuit for high gain, low distortion and very low output impedance by using a variation of the White Cathode Follower. The circuit uses no negative feedback for more natural tonality.
http://mystere-usa.com/index.php?option=com_content&view=article&id=91&Itemid=167
http://mystere-usa.com/index.php?option=com_content&view=article&id=91&Itemid=167