Which Skar Sub for my box

[Wyatt660r]

As of right now I have a Skar SDR-10 d4 in a 1.5 cft box powered by a Wolfram c2400. I was wondering if I would benefit from getting a SVR 10 or DDX 10. I know th SVR requires a bigger port but not more air space and the DDX requires more air space but not a bigger port. I didn't know if I would get more bass or if the subs would be choked too much.