If you're getting the 4 15inch lvl dc's you would better take the 10k amp, because they are going to be underpowered if you take the 8k amp.
But you need enough battery's and the electrical.
they have nice (car)subs, and speakers for home audio.
I have an old sub from them and it sound really clean,can get low and will hit a few deebeez.
They say the new CV subs are hitting kinda hard, but they are SQ -SQL subs.
I would also go with the choice of cerwinvega, i have a old cerwin vega sub in my room and it doesn't need a whole lot of power to bang.
And that Vmax is a nice SQ-SQL sub.
I don't know how to say it in english but i'll give it a try,
I used (thick) double sided tape to seal my enclosure behind the sub.
something like this: