Right my mate is getting a a Mercedes C220 CDi and he wants to add a killer audio system. Hes chosen the subwoofer but is not sure what amps to go for.

The subs he is going for is 2 Rockford Fosgate Power S2 T215D4
hes getting the enclosure custom made to match the black leather interior. So what subwoofers does he need to power these?
The head unit is a Pioneer FH-P80BT CD/MP3 Double Din Unit With Bluetooth

He needs an answer asap. so thanks in advanced.

your friend will need one hell of an amp for those. Considering He bought a mercedes with very expensive subs, i'll assume money is not an issue. That being said I would recommned JL Audio Slash v2 Series 1000. This Amp will put out a thousand watts rms and will be extremely loud.