The seat lift is a good idea even in a down firing enclosure. If all the weight is on the box it will be getting pushed down into the padding of the carpet giving the subs less room to breathe. The seat lift is a win either way...
t22a80 said:170 Wrms for a comp set isnt too crazy. The amp I have is 270 wrms and I have that powering a set of CDT comps. Do you really need that much power, probably not but it provides extra head room and will help you get the ful potential out of them. Remember its not watts that blows speakers its distortion. Granted you probably dont want to try and hook that amp up to a set of comps that says 50wrms but any of them that say 100wrms is fine.