Vandersteen 2w or 2wq's

the Q IF you can put filter between pre and amp or if your integrated as this feature.
spend some quality time at Vandersteen website
the FAQ section under support
The line level preserves amp transfer function and will result in better sound.
I had 3 A sig for many many years...
Personally I would flip them for a pair of used Model 5... there you get the better filters, much more capable subs, 11 band EQ, etc..
But I also understand the appeal of a $500 sub
l

the 3a sig which i owned for a decade put out significant and high quality bass...tuning to room involves some work but so does any speaker..the manual is a great place to start. Do you have a Vandy dealer nearby ?
you might also invest in an analog Radio Shack SPL meter and download the Vandertones. You dont have the Quattro EQ but you can tune via movement. Use your ears also.
i dont think RV spends too much time here, thank him on the Vandy FB page..he might see that. 
you also have Rutan commenting on your thread he is IMO top 3 Vandy dealer in USA.

Soular Energy..Ray Brown
do not be caught placing speakers without it...

i happen to be an Audioquest fan. I am sure others will weigh in on cables. Low of AQ and Richard Vandersteen share the DBS patent.

Even tho your placement option are limited you can still download vandertones and buy the analog meter shack spl meter and tweak sub location to tame humps and suckout....
You will be suprised how unflat your room is..every room...
This will of course eventually make you want a pair of quattros or better..but hey..
Btw pair of quattros on the gon less than 5k with 11 band eq below 120..
Call me a fan boy..
Have fun 3a sig most under rated giant killer out there..imo..