Sub Suggestions

The Rockets do have parametric EQ on board, which is very helpful when setting them up. If music is most important to you, I think you will love it. Very compact also.

Rel Acoustics makes some excellent subs. I don't know what the Aerial SW 12 costs, but the Rel Storm 3 can often be found right here on Audiogon for around a thousand, or so. I own a Rel Storm 3 and love it. Quadophile has written an EXCELLENT review (right here on Audiogon) of the Rel Acoustics Strata Mk III. Here's the link to it:
Rel Strata Mk III: Review by Quadophile

The Rockets are a nice value but they aren't in the same league for sound quality as your Ariels.

A better match sonically would be something like used RELs, or used Nola Thunderbolts. These go plenty low for HT but are better than most for music as well.