Audiotomb,
I would give JL audio's new crossover a try if it is in your budget. It is an analog/digital hybrid and gets good review (linked below). Bryson also makes one but it only has 12db slopes (I believe) and IMO a crossover with a 24db slope will work much better.
http://www.ultraaudio.com/index.php/equipment-menu/537-jl-audio-cr-1-active-subwoofer-crossoverDbtom2,
The OP is stalking about the F110 that does not have the active crossover and only has a low pass filter so he will need an external crossover. He will have better potential sound with the F110 and external crossover because the f110 has the DSP to flatten the room nodes.
With that being said I am using two E112s with the internal crossover highpassing between my preamp and amp with great results. I feel their crossover is extremely transparent. The only down side is the E112 does not have DSP which would help a lot.