well dont get worked up, car audio purchases should not be made in the course of one night...slow it down, read some stuff on this site, you see there are at least 2-5 posts like this a day, people looking for "the best" sub to run...RE is a great place to start, im a fan and an owner of their products...
not everyone here will agree with they favorite picks, its all about the person...you seem to know a bit about what your looking for, so just read up a bit more on the site here and im sure you'll get all your questions answered...
also you don't have to go new if your decision is hung up, you can buy a few different one here in the classifieds and try them out, like i do...
holla!