The 8b’s magnetic-planar panel is a mostly-resistive 11 ohm load, the woofer 8 ohm. If you bi-amp the speaker (you really should), the panel prefers a voltage source, so any of the good modestly-powered (75-100w) tube amps will be fine. The woofer prefers current of course, and 100 watts of solid state should be fine. What’s the cubic foot volume of your room, how is it furnished, how loud do you listen, what’s your music, etc?
As for which amps, do you have a budget? If you need to go cheap, a nice little used tube power amp (or pairs of monos) by Quicksilver or VTL will be great. If you have more to spend, a pair of Atma-Sphere M60’s might be great (as I said, the panel is an easy 11 ohm load looking for voltage, not current), and a Music Reference RM200 or RM9 will definitely be. There is a nice RM9 on Audiogon right now at an asking price of $2200. Can’t do much better than that! Four output tubes per channel for 125w, and in an RM9 the tubes last forever, unlike some other amps I wouldn’t recommend. For the woofer, any old 100 watter should be fine---the x/o from the panel to the woofer is at the very low frequency of 180Hz. How ’bout an old Adcom 545? Just make sure it’s output capacitors are still good.
Take a look on the Planar Speaker Asylum Forum for "Daveys" easy cure for the woofer’s high-end (around 150Hz) electrical resonance---the simple addition of a single part to the driver’s terminals (Roger, how could ya?!). Get the speaker five feet out into the room, and listen to the highest-value speaker available today---it leaves the similarly designed (in some ways) and priced Magneplanar MG 1.7 in the dust. But you already know that!
