I have an Ibanez RG450DX, and I am replacing the pickups. It is a HSH guitar, I've decided on getting a D Activator pickup for the neck and bridge, but I am still looking for a middle pickup. THis guitar is mainly going to be used for shredding, so I want something that is responsive to tapping and has good harmonics. Would it be better to get a stacked humbucker or a single coil for the middle? Which pickup should I buy?