In that room, I would do ported, and I would go with dual VTF3 mk5s. The sound quality on the VTF3 mk5 is very high, I can attest to that myself. Dual VTF3s will have a much easier time with material below 40 Hz than sealed subs, so less strain and less distortion- the type of strain and distortion you have already heard from your Epik. In a room that large, sealed subs will not benefit from room gain, so the low end would have to be boosted to be even with upper bass, and that is a real strain on sealed subs. You can also configure the VTF3 to get the sound you want, it is not stuck with a fixed sound.
A couple of other things...
Do NOT get the harrison pass labs filters: passive filters change the resistance load of the electricity and can potentially change the character of the speaker sound and efficiency. It's like adding a whole new unexpected component to the speaker's crossover. If you want to keep things simple, get a
Hsu high pass filter, it is not expensive or complicated, and it will get the job done without messing up the line impedance. A
miniDSP would be able to do that also, and give you a lot more flexibility, although its a bit more involved, but here is a
guide to use it for subwoofer crossovers to help you get started.
I also recommend you use a higher than 40 Hz crossover. Yes, your speakers can play down to 40 Hz, but they have nowhere near as easy of a time as a sub. Use 80 Hz, that takes a big strain off the speakers. A good sub like the Hsu's will play 40 Hz much more smoothly than your speakers. This is especially true since you like your sound loud. If you like punchy mid bass, get dual subs and raise the crossover much higher, 120 Hz, although I would want the subs respectively co-located with the speakers to prevent localization.