Well it depends on what sound is consider good to you. W0 is affordable but it's a beginner's sub. I had a pair of 12's it sounded decent but not good enough. Also had a pair of 12w6 I loved the way it sounded. Loud and clear. How ever w3 seems to be a little more boomy but a little less of an SQ sub compared to w6. That's just my $.02
The good thing about JL audio is the name. Meaning you can start off small and work up, with no problem selling the line you no longer want. I would say if you go with a [email protected] you should be fine. The wonderful thing about the PG amp you are looking at is that it is 1ohm stable, meaning that if you get bored of 2-10's you can always go with 4-10's for the little extra "thump". Speaking from experience
HOWEVER, FIRST THING YOU SHOULD DO,
is figure out you are looking for CRAZY BASS, that people can hear down the street then consider going with 12's, but if you like a CLEAN bass (nice and tight) then I would say go with the 12's. If you like dance/techno or metal then I would say either way you would really have to go with 10's, but if you like hip/hop, r&b or reggae you could get away with 12's. I listen to everything, but I love CLEAN BASS, with balanced mids/high's so I would still say go with 2 10's and then work your way up to 4.
with either subs you can't go wrong. W6 are dual 6 ohms so with a pair you'll have a 1.5 ohm load. I had 1200 watts going into a pair of 12w6 and it was dangerously loud and clean. Put them in a sealed box. The nice thing about the w6 is that it doesn't need a hole lot of space. 1 cu ft per sub will give you great SQ but will hurt your chest as well. A few months ago I had a chance to demo a single 10w3 in a ported enclosure with 400 watts going into it and god **** that thing was loud. But then again it was in a demo room how it sound in your car will be different. The good thing about our legend is that you'll get better bass due to the leather interior and room lining. Bass bounces off hard surface better than cloth so generally it'll sound better. I guess my point here is that you won't be disappointed with either subs. the W6 cost a little more than the W3 so go with either sub. I went with W6 because it is the flagship product for JL for very long time. Mostly for bragging rights but at the same time I was happy with the result.