Leftistelf, to be honest, I haven't tried any real high end linestages in my system. I know one thing, though. It is going to have to be a good quiet one. The high efficiency speakers really show up any problems with the noise floor very quickly.
If I were to venture a guess as to which might be a good match, I'd mention the Supratek preamps. They have been really well received by alot of members who have bought them, and they make an excellent synergy with the Berning amps, according to what has been stated on that "Preamp Deal of the Century" thread. Everybody seems to think that these preamps are really performing in a very high-priced category, but are still affordable. Maybe you could even get into their top of the line Grange model. At any rate, I'd investigate these Supratek preamps, if I were in the position that you are in now. Nothing is perfect, but these seem to be regarded as coming pretty close to it, at a reasonable cost.
If I were to venture a guess as to which might be a good match, I'd mention the Supratek preamps. They have been really well received by alot of members who have bought them, and they make an excellent synergy with the Berning amps, according to what has been stated on that "Preamp Deal of the Century" thread. Everybody seems to think that these preamps are really performing in a very high-priced category, but are still affordable. Maybe you could even get into their top of the line Grange model. At any rate, I'd investigate these Supratek preamps, if I were in the position that you are in now. Nothing is perfect, but these seem to be regarded as coming pretty close to it, at a reasonable cost.