While i cannot comment about AMP etc, For the HU And speakers, I have Kenwood DPX-MP5100u with Blaupunkt front & Rear speakers installed in my baleno and they've worked well since past 3 years now so keep these 2 in mind too while shopping !
Link for DPX-MP5100U : Kenwood Corporation | Car Electroics | 2DIN Receivers | DPX-MP5100U |