can sum1 help solve my problems????
i've got a x15c4 kicker sub an im not sure what size enclosure i should use, i would also like to know what amp i should use im thinkin bout a 4x100 jaycar but not sure, could sum1 help point me in the right direction.

any help would b greatly appreciated

Ok, based on the specs in bassbox pro (Fs - 19.98 Qts - 0.484 Vas - 430.4L) That sub is suited to BIG sealed boxes. Something like 114L, or at least 85L if you can't fit 114L easily..

Amplifier wise, I'm assuming you want a 4 channel amplifier so you can power your front speakers as well as the sub? (The specs suggested the sub was a single voice coil model)
2x100w for your fronts and 300w for your subs should be ok.