EA Iamp Micro setup - slave w/ power amp questions

[J33Bass]

I have the EA Iamp Micro - @4 Ohms, 550 Watts, @8 Ohms, 350 Watts. It has 1 speakon out.
(this is a wonderful piece of equipment, both for electric and accoustic!!)

So far I have only been able to use this head with one cabinet and am very interested in using two.

I have a Carvin RL 115 - 4 Ohms, max power 600 Watts
and a Carvin RL 210T - 4 Ohms, max power 400 Watts

I would like to run the EA into the 2x10 cabinet normally and slave it out to the 1x15 using a QSC RMX 850 2 channel power amp. (output power per channel / input - 270 watts at 4 ohms)

Firstly, is this possible? and how would it be wired?
Secondly, is it possible to set a cutoff on the 1x15 and approach it's use as a subwoofer? I want to use the 15 to get a lot of bottom, pushing lots of air in an attempt to emulate the Hammond Organ foot pedal sound in tandem with the normal tone through the 2x10.

Thanks,
G