Can't really offer any detailed advice without the relevant info....
But, a stock Clio charge circuit in good order should be able to support around 1kw rms in a daily driver playing mainly music....
To gain a better idea you could ADD all the claimed amplifier rms figures together, (thats at the impedances you will be using), then half it....If this figure is below 1kw rms then under normal use you should be fine, (assuming you use the correct sized power & earth cables)....
The options open to you with regards upgrades are either a larger capacity starter battery or an uprated alternator, (or if going with big power then added alternators).....