Which subwoofer to buy for ALPINE PDX 1.1000 mono amp ?

I own a fiat grande punto and like to install a subwoofer . i Already have an ALPINE PDX 1.1000 MONO AMP . which subwoofer do you thing would go fine with this amp ? i like the jbl cs1215 , soo was thinking of going with two of the jbl tubes since with two i'll be getting 500 rms , are they any other brands that i can go for that will give me deep and intense b or can i stick with buying 2 of the JBL CS1215 T to do the trick ?