No they won't be, especially if you are amping them up. They have a piss poor RMS wattage and probably wouldn't take the power of an amp for long (though I could be wrong).
I can't believe you'd contemplate upgrading your audio setup and not replace the factory speakers, it's crazy!! Plus if you keep the standard fronts and buy 6x9's they will completely overpower the sound in the front and you will hear everything coming from behind you.
Use the money set aside for the 6x9's to buy new fronts, even if they are only coaxials. You wouldn't believe how much better a pair of speakers sound over the standard Renault ones they put in, even just running off the HU never mind an amp.