We try - glad we could help.
I didn't get a chance to reply until now, but I'll offer a thought that may support your decision to go with the LFM-1. Prior to getting my LFM-1, I ran an SVS 25-31PCi - a very similar sub from a performance standpoint, albeit very different looking (and, at least to my ear, the LFM-1 has blended more seemlessly with the rest of my system than the 25-31PCi did at the same time that it has blended better with the wife's furniture). The SVS was first used in our old house, where the living room was 11x19x8 - or about 1670 ft^3 (not much different from the 1440 ft^3 you're working with). Based on that experience, I think the LFM-1 will be a good fit for you while also remaining sufficient for your needs if you relocate the system into a larger room.