6.5" speakers, 800w

[Llew]

I'm looking at buying some 6.5's, 800 watts, and i'm not really sure whether or not thats all i need to fit them ? I know how i'd fit them now but is there anything extra i'd need, such as a head unit.
Do i just connect the wires from the radio/ dash speakers to the new ones ?

[ash 1.3 sr]

You need an amp and wiring kit

[L14MNP]

800 what? lol lol

[ash 1.3 sr]

Yeah if there 400w rms each you'll need atleast an 800w rms amp