Sub For Martin Logan Aeon's

Im about to audition the Martin Logan Aeon speakers in my home and I'm aware that a sub will be required if I want to use these speakers for music of all kinds and theater. I'm concerned that the subs out there will not be fast enought to keep up with the MLs. Please give me your recommendations or experiences with sub matching. PLEASE ONLY RESPOND IF YOU HAVE EXPERIENCE WITH THIS ISSUE.

Thanks!