AVI makes a great SQ 8" sub/midbass driver if you have the room. Probably the best 8" I have heard for SQ... Not an excursion monster though.
Every once in a while an older Adire set of 8"s come up for sale. XBL2 is a good thing. Might be worth checking out.
For a slim 8" the Rainbows get rowdy.
The Anarchys are much more musical than people think from the spec sheet. Give them a shot. Size is 6.5-7 oversize range.
... I ended up with CDT M6 Gold 6.5" midbasses due to installation constraints. We'll see in a couple weeks how they do.
2007 Cadillac DTS: AT400.1 + 15" Brahma
Daughters 2003 Saab 9-3: In progress!
1979 Porsche SC: Kenwood X-994, PG M50, PG RSd comps.
1971 Chevy C-10: wind noise