ReptarXJ

So my 96 Sport I found out has a blown rear soundbar speaker that I'm looking to replace with 6.5" and 5.25" for the fronts but thought I would like to have better sounding low end while I replace all 4 speakers as aftermarket speakers aren't designed as full range like factory. I already have a sony head unit installed and I'm of the mentality of upgrading everything while I'm in there. I wanted to hear peoples experiences with powered shallow subwoofers that will give clean bass that will fit either under the passenger seat or under the (preferred) rear bench seat. I'm looking for a good value solution under $200 and don't want to go above.

Some considerations:
NVX QBUS8v2 Under Seat Powered Subwoofer Enclosure with Integrated Amplifier

Kenwood KSC-SW11 Compact Powered Subwoofer

Sound Ordnance B-8PTD