what do you think is comparable to JL 12 W6v2? And do you guys think I will get more output form a single JL 12W7 or 2 12W6v2 subs with the same power?

 

a boston G2 12" is probably pretty damned close to a 12w6v2 in every category, except cost. the boston will cost less than half of a 12w6v2. a DD 3512 will absolutely smash a 12w6v2 or be noticeably louder than a 12w7 in sheer output. it won't play quite as cleanly as the jl's, but will still be very musical and accurate. but in terms of raw output, the jl's can't touch the DD's. a 9512 will smash anything jl makes in output and ask for more.
as far as a 12w7 and a pair of 12w6v2's... what kind of amplifier do you have, what impedence does it make the most power, what kind of music do you listen to, and what kind of sound are you looking for. i've done single 13w7's that will hurt you, and pairs of 8w7's that are tuned to just fill in the bottom and, and do it verrrrrrrrrrrrrrrrrrrrrrrrry cleanly. done a pair of 12w7's off a pair of directed 2400d's and that car seriously hurts to sit in it. but keep in mind that JL audio subs are not designed for spl purposes... they are designed for SQ and just happen to bang pretty hard. jl designs around transient response, low freq extension, etc etc etc to make a clean product. they just happen to get loud