Power from old stacker to an amp? and sub question

[vs calais 95]

I have just taken out my 10cd stacker from my VS Calais, I am wondering if the power cable that was used to power the stacker would be able to run the amp that I am going to put in place of the stacker? (I don't currently have an amp, but when I do powering it throught the old stacker power cable will be a time saver!)

Also, I have a sub my mate gave to me but I haven't been able to test it and thought I'd ask to see if anyone knew whether it is any good or If I should get something else, the brand is "Megavox" and the model is "MGX-1200" it is a 12" 500watt sub.

Any info on sub/amp/speaker install in regards to my make and model are also welcomed.

Cheers.

[vs calais 95]

Just a couple more questions..

As I already have the sub, should I just buy a ready made box or would it be worth making a custom box so I have some more room in the boot? I have heard custom boxes can be pretty dodgy, is that because they are simply made shitty or because the sub isn't suited to it?

and I was looking in autobarn and they have the steering wheel wiring/ISO harness so that I can use the button on my steering wheel, does anyone know if these are easy to install? They are also $100, pretty expensive if you ask me!

[MiggzvsC0MM0D0RE]

Custom Boxes are good if you make them right Rockford Fosgate® - Woofer BoxWizard this helps alot.
The sub isn't to bad but if you want it to last i get something more reliable.

[VR_Acclaim]

For that sub prefab box...and I dont think the power idea will work