Got mine from Halfords, (Kenwood Elec KFCW300) doesn't matter about the make though, so long as the depth and size fits OK, any ICE Disti would be able to fit it if they offer the service.
You could always PM "Mr Singh" as he owns his own ICE Company and would most likely beat any of the local sellers for price and could give you better advice than me aswell.
This basically what I'm running in mine, gives good low end bass without blasting the outside world to piece's -
ICE - Alpine CDM9807RB Head Unit, Alpine 400-Watt Amp, 400W- Alpine 12 Sub", 300W Kenwood Sub, 70W 7" Mini Sub Speakers in Each Door. Full AV system with 10 Disc DVD changer and TV.