Because I purchased my subs before Outlaw had either LFM on the market, perhaps an actual owner/user could offer a better opinion than I, espcially if they have a home theater space similar to yours, but IMHO . . .

Outlaw's LFM's have a pretty good reputation for delivering good levels in the most important bass frequencies.

Quick comparison:

• 1 x LFM-2, $299, comparitive SPL 110db, 28-180 Hz
  2 x LFM-2, $549, approximate SPL 113db, 28-180 Hz
  1 x LFM-1, $579, comparitive SPL 115db, 25-180 Hz
  2 x LFM-1, $999, approximate SPL 118db, 25-180 Hz
  
  Hybrid combination of one LFM-2 and one LFM-1, $799.

Then there are other products one might consider as well, but not many have as much bang for the buck.

If I were considering which Outlaw sub or subs to purchase, and could spend around $600 with shipping, I would likely choose one LFM-1 over two LFM-2's - more SPL and just a bit lower frequency extension. How loud do you like to push your system? If I had just over $1K to spend and wanted people upstairs to occasionally think an earthquake or tornado was coming, I'd consider two LFM-1's, although one forum contributor who bought two LFM-1's reported that one LFM-1 was plenty for his situation. Be very careful unpacking and testing so that if one LFM-1 is enough for you, the second can be carefully re-packed and returned or sold in 'new and tested' condition.

I hope all goes well for you.