Please help w/crossovers McIntosh/EW theater

My theater is 25'x25' with an asymetrical cathedral ceiling. The room is fully acoustically treated. I listen at relatively low volumes so I would like it set up optimally for low to moderately/ low volume listening.
The theater equipment consists of the following:
McIntosh MX151 Processor
McIntosh MC303 amp (left/center/right)
McIntosh MC207 amp surround back/sides.
L/R Egglestonworks Andra ll 17hz,
Andra center -3db at 78hz,
Side surround Egglestonworks Fontain ll -3db at 36hz,
Surround back Egglestonworks Katherine on-wall -3db at 42hz.
Subwoofers: M&K MPS-5420 (prof) 16hz, at front wall centered
Rear sub M&K MX5000 (prof version) 16hz, at rear wall centered
Side subs one at left wall, one at right wall M&K MPS-2810(s) has two 6" drivers per sub, around 30hz cutoff (I would guess). All 4 subs are driven by 1 lfe output on the processor via a McIntosh xlr splitter (works well).

I know some of this is trial and error, but any advice would be appreciated.
I realize that the phase of each sub should be tested first. The largest dilema is dealing with the Andra ll and the subs. They both go very low. I shouldn't over lap the bass correct? Ie cut Andras off at 40hz and lfe at 60hz? Will the 20hz overlap cause issues as the L/R Andra ll bass will interact with the M&K woofer bass between 40 to 60hz?

1)What do you recommend I cut the Andra lls at?
2)What do you recommend I cut the subwoofers at?
3)What do you recommend I cut the other speakers at?

Thanks for any advice.