help me choose subs

Im planning on putting a system in my car in a couple weeks. Im buying from a local shop instead of online.  The shop carrys Orion, Memphis, JL, Xtreme, and PB.  Ive already ruled out the JLs b/c I want SPL over SQ.  So im considering the Orion C series, or the similar priced Memphis or Xtreme subs.  According to the guy i talked to at the shop, the Xtremes use to be know as Cobalts, and they are made by Orion. Has anyone had experience with these subs?  Which of those three subs would you recommend?

Go with orion, not a big fan of xtreme or PB, and i just think for SQ orion passes memphis but a hair, but that all depends on which seriers. Alls of these subs, even the JL's could be awesome SQ subs if powered and boxes right. If done wrong, even the nicest sub will sound like complete crap.