Complete installation f. golf 3

hello! I’m looking for a complete system (apart from a headunit, which I already have) for my golf and hope you can give me some tips. in clear text: 4-channel amp + front-ls + sub (finished box, I’m not so the handcrafter). the whole should move in the price frame from 700 to 900 euro. hope the basic idea is ok and I’m not on the (acoustic) wood path. listen mainly to rock, from time to time some techno gets lost in the c d-player. are the complete systems, as you can find them at www.bigdogaudio.de, something? some would fit into my price frame… e.g. this candidate. thanks in advance.