You asked what subs would be as good in the price range, so imma tell you. I run sundown sa12's and love them, and they would seriously save you some money compared to 350 each for the Memphis m5's (of which I honestly am not that big of a fan of) or heck for that price you could look into some less massively used brands (as compared to kicker alpine rockford fosgate sony mtx etc...)such as obsidian, incrimminator audio, FI, re, earthquake, treo engineering, digital designs(amazing subs), d.a.d, ppi(a dealer named trumpet can help you out on here for pricing and ordering stuff from them, very solid stuff for the price), massive audio, etc... As I tell people all the time who are new to car audio and wanna have an impressive system, go crazy on your brands and don't just get what everybody else has. For example, I'm known around my parts as the dude with the treo engineering subs. Just mix it up bro, hope this helps.