Its all down to the price you want to spend... diffrent people like diffrent sound, some prefer the quality and some like it bassy...
Iv got a bit of both in my car good sound quality and more than enough bass to make you turn your head...
If your on a bit of a budjet look in to the vibe active subs or even the Fli, i wouldnt go for Fusion tbh...
Check out
www.caraudiosecurity.com or .co.uk they have some good deal in there also look in the back of the fast car/max power mag for deals in other audio shops..
if you can stretch to £500 go for some of the MTX gear or save a little and go for Diamond audio..
If you have a bigger budget go to the high end of audio like JL or Focal. My only advice would be not just to listen to what people say to you about 'oooh my m8s uncles brothes cats owner has these subs and they loud son' loud isnt good if theres no quality in the sound..
Try and have a listen to a few set ups that people are running 1st in theyr cars find one you like and go from there.. If you didnt live so far away id happily sit you in mine for you to listen...
I bought my stuff from DB audio in cardiff, the guy in there sat me down asked me all sorts of questions on what id like. if i wanted ported or sealed boxes, if i wanted quality or bass ect i was confussed to the max, but he took me to a few of the cars he had done that day including his and i got to listen to what set ups where givng out what sounds ect....
came away from there with a very light wallet and a big ass focal set up..and im happy as larry!!!!
its really up to you though m8y