Just a quick response on the topic of bi-amping.
While the issues can certainly be debated (and tested), one things is certain - using a single amp is fool-proof (the crossover does the work). Bi-amping, while certainly possible, introduces potential level errors due to different gain structures in the associated amps.
Using different make and/or model amps can really make if difficult to get the gain relationships correct without resorting to test and measurement equipment.
With a multi-channel amp, this problem should be minimized (provided the channels are consistent, which they should be). But now you have to look at the power supply. Is it robust enough to supply all the amplifier channels with all the power they require?
Take using the Panasonic approach mentioned above, for example. Regardless of how many channels are used, the power supply is only capable of of supplying a given amount of instantaneous power to the amplifier circuits. Once this is exceeded, it makes no difference how many channels of amplification are used.
While I have never had a problem driving HT3's with a Panny at moderate levels (I own and often use an SX-40), it does not have a very robust power supply. Since this is the limiting factor, I am not sure that bi-amping with one would provide any significant benefits.
Keep in mind that the tweeter requires very little power. Most of the power is consumed by the woofer.
Although I have not had time to experiment with it, I have often thought of using a high-power SS amp for the woofer and smaller tube amps for the midrange and tweeter. With DEQX, this is very easy to control. Simply hook the chosen amps to the appropriate drivers and measure them. When the crossover is created, the levels will be optimized automatically.
You could end up with a very nice musical tube sound, yet have all the power required to avoid any hint of clipping in the woofer section.
Just a few thoughts...