I can't really help you here. I am using a 10 year old B&W ASW 500 sub which is pairing up nicely with the AMP. I was thinking about getting the matching sub but some of the people i speak to are say that I should stick with what i have.
If i had money to burn and a sub that looked amazing I would go for the B&W PV1. But i have also heard the MJ Acoutics Pro 50mkii and this for the money sounds good. Just test a few and you will know whats best when u hear it.