Which to go for .

[ipswich1.8t]

I have a couple of options reguarding fitting a sub in the boot . Option 1 , i have a couple of JBL cs10's brand new which i have had floating around for ages and kee p thinking i should use them , but i've been told they are not the best , a bit cheap , or option 2 is one of these

http://cgi.ebay.co.uk/JBL-12-GTO-1200b-SUBWOOFER-SUB-IN-FACTORY-FITTED-BOX_W0QQitemZ260479111257QQcmdZViewItemQQptZUK_Audio_TV_Electronics_In_Car_Entertainment_GPS_Car_Speakers_PP?hash=item3ca5c3d059&_trksid=p3286.c0.m14

which i also already have . This would be a lot easier to lift in and out of the boot in case of emergencies , where as a larger box with 2 10's would be a lot more hassle , but would probably sound better .

I also need an amp to power either option , and advice would be very helpful ...

[jamie16v]

more is not always better. i had two tens before the single 12 i have now and the sound is alot better.  all depends in the quality of the speaker tbh.
stick with the 12 in my opinion.
as for amps then get the best you can afford.. im using alpine v12s and they suffice!

[B-chi]

Stick with the tens. Build a descent box and they'll sing for you

[Shady Pioneer]

Depends on if you want the ease of getting it in and out or not. If you do then you need the single, and tbh, 1 sub is good enough to provide a nice sound experience, but if you want it louder and bassier you'd wanna go for the two. However that being said, you need to make sure the amp is powerful enough to do both and also make sure you front speakers are uprated otherwise the bass will most likely drown them out.

[Len]

Also it depends on what kind of music you listen to most.

If its a variety I would go for a single 10".
If its say hip hop or R&B then more likely the 12"