I have to be honest, I have always respected Sony for their electronics, but not their speaker manufacture - I have never heard a set of Sony speakers that genuinely impressed.
I would agree with all the other responses - look further afield.
However, until I know what amp you're using/intend to use, I can't give a recommendation. At the end of the day, any box you have can be modified so as to match the subs requirements, so match a sub to the amp, and forget the box for the moment.
Even if the box is really worng for the sub (which I doubt it will be) you can build another one for ?30. However, spend ?150 on a sub that is killed by your amp (because they weren't correctly matched) just because it matches the spec of your box will be an expensive and needless mistake.
I agree with that Overseer and Veedubgti8v that JL are incredible (just look at the amount of sound-offs are won with that gear) but if you intend to use a 25wrms un-branded amplifier that would struggle to stretch the standard fit speakers, then you'll kill it in a day.