New to Bi-amping, Crossover and Tube amp

I have decided to bi-amp my speakers this is my first attempt, and I would appreciate some opinions. I was thinking of using a Marchand Xover and a Cary 120S for the highs, and keeping my beloved Cary CAD 500 MBs for the low end. I have Maggie 3.6R's and want some opinions?

What Machand Xover, or is there another suggestion? Also, is the 120S enough to power the mids and highs on the Maggies? I also thought about a VTL or Rogue, but I love the sound my Cary gear makes with the Maggies so thought I would try to continue the trend.

Suggestions and advice is welomed and appreciated.

Magnepan recommends:

Low Pass: 18dB/octave at 250Hz
High Pass: 6dB/octave at 200Hz

but there is some room for flexibility on both slope and frequency.

The Bryston 10B can be very flexible. Magnepan has (or had)it's own XO1 that can adjust for levels but they're getting hard to find. Marchands are very good but you really have to discuss your requirements with them.

Mixing different amps, even from the same brand, is an adventure. Even more so, mixing SS with tubes. However, the 211AE's did have nearly identical impedance to the 500's. Don't Maggie's like lots of power on both sides of the xover?

I haven't worked with the Maggie but the 3.6, being a 3-way, means you have 2 crossovers to deal with, so the external passive xover can't be abandoned completely.
How's this for a direct answer? Worth a deeper look over there.
Good stuff, thx.
I don't beleive this to be correct Ngjockey. In bi-amping the Maggies with an active external crossover, you do abandon the Magnepan external crossover and just use the internal crossover for the Mid's and Hi's.
As I said, I've never owned or worked on Maggies. I was just assuming the mid/hi xover was part of the external passive since there isn't a lot of room on the panel. Even better, no surgery.

I Should be more specific and point out that it's the Bryston 10B Sub and they are available in both RCA and XLR versions. Looks like the Marchand would be less expensive unless you can pick up a used 10B Sub.
Almost forgot about the Pass XVR1. Excellent and very flexible but costs more than your speakers. In the same price range, there's the DEQX processor/preamps that have digital EQ/room correction features and very steep slopes. Either are not simple to use but do not require changing boards.

At the other end of the scale there's the pro units like Rane and Behringer but it's debatable if they would be an overall improvement at your level of gear.