Jl fathom f212 diy vs JL's version

Looking at redoing my subs on my stereo which is presently a pair of mirage subs of some model.... They are my wife's and each have a single 8in driver. They sound very boomy.... Cannot play deep and well... I don't like them :). Presently I only use the sub for ht due to not liking how they sound. Ideally I would like to use the subs all the time.....

So I want to get something different. Went to a local car audio shop where I know the owner (talked to him about my car setup) and he said he would sell me a new fathom f113 for $2,500. I know I would need two of them but it would be a while before I could afford a second one.....

Or.... Make one myself which is what the owner of the shop said he would do. I thought I could use a 2 pairs of the jl audio 12w6 subs vs the w7's they use in their home theatre sub line. I would have around $1,600 in four 12 in subs so going this route it would be more like a f212...... And I thought I would use wyred 4 sounds sx1000 to power them, or possibly the mono block version.

Is the room correction stuff worth that much added cost? I have a integra 80.1 pre/pro, old infinity kappa 8.1, 5.1 and kappa video speakers presently powered by parasound hca1500 amps.
Kinda leaning towards trying a funk audio sub's however unfortunately It doesn't seem like their are many reviews

I can get about 40% off a new JL sub.... Not sure what they would do if I get a pair of funk audio subs... 15.3's is probably a better option vs the 18.1

A pair of 18.3's is out of my budget :(
You should check out Mark Seaton's Submersive subs. They are head to head or even slightly better than the F113's.
In answer to one of your questions, the effectiveness of the room correction stuff on the JL subs really depends, in my view, on where you cross them over. I have set the crossover very low in my system (about 35Hz), and in that instance the room correction was of no help (my room has a resonance at 63 Hz, and the correction did not help, as my main speakers are causing the resonance, not the sub). If you cross over higher, it might make a difference. I'm sure there are others here who have used the room correction, maybe they can share their experiences.