Subwoofers and Crossovers.

My system is Cary DMS-550 / Luxman L-507uxii / Spendor D7.2

After researching I decided to add an active crossover and two stereo subs to the system.

1. I am looking at JL Audio CR-1 as the crossover.  This will take the pre-out from the Luxman and feed mains-in and setup the Luxman as separates. Is there anything else that I should look at?  I am only looking at analog solutions.
2. After looking a REL, Rythmic, SVS, Martin Logan and JL, I am leaning towards getting two JL Dominion D110s.  Would these subs be sufficient or should I be getting JL E110s? I won’t be using the internal crossovers, so primary concern is fidelity.
3. If I am unable to treat the room properly, I may be introducing a DSP solution just for the subwoofers.

I am looking for some advice from people who have walked this path before me on both the active crossover and the quality of D110s. 

I would appreciate any advice on this process of integrating subwoofers into a two channel audio system.