Active CrossOver for Biamping Maggie 2.1's

I have a set of 20.1's on order and plan to bi-amp them using an active crossover. I am thinking about getting the Bryston 10B Sub for this purpose which I understand has been recommended by Magnepan and is an audiophile grade component. I would appreciate it if someone could advise me of the crossover points and slopes for the 20.1's. Also, I would be very interested to hear of anyone's personal experience with the 10B Sub or any other active crossovers.

Other components in my system are Aragon Pallidum II amps, Aragon 8008BB amp, BAT VK-50SE preamp and VK-D5SE CD.
Great question! I am looking to do the same with my Maggie 3.5s. Is the Bryston 10b Sub or the plain 10b model recommended for:

- 2 speakers and a Sub?

+ and - please?
Magnepan recommends the 10B Sub since they do not recommend splitting the high and midrange. Hence the crossover splits between the low panel and the high/midrange panel. The 10B sub gives more frequencies in this range to choose from.

I'm now getting intrigued by the Marchand XM126 tube crossover which can be had with almost any combination of XO frequencies and slopes. It has received some very nice reviews. Since my system is all tube up to the power amplifier (BAT VK-D5Se CD Player and BAT VK-50SE tube preamp) the idea of staying with tubes in all the front end gear is appealing. Many Magnepan users feel very strongly about the use of a tube front end followed by SS power amps as an ideal combination. Some even go with a tube pwr amp for the mid/highs in a bi-amped configuration.