My personal opinion is Rythmik F8s, or dual single driver version as I have, are easier to blend than bigger subs. Rythmiks extend up to 200Hz (and down to 30Hz). My Rythmik plate amps have a switch between 12 or 24db rolloff, low pass setting, volume, phase, and more. In my previous setup, I ran these along with a pair of Rythmik F12s that go down to 14Hz! They were easy to blend with the eights which were easy to blend with the SAMHOs. A bit more of a challenge to blend F12s alone with the Omegas.
Louis, however, designs his subs to mate with his speakers from the ground up, so there should be little obstacle there.