No worries!
I'd avoid a parrot kit as it uses it's built in amp to power the speakers (via the necessary SOT lead) results in less than satisfactory quality (at least for me anyway).
Slapping in a new amp isn't as drastic as it seems, though I would recommend you find a competent car audio place to help you with that. (Can't stress that enough, I've seen so many people end up paying twice to have a job done because one shop couldn't do a proper install).
As for amps, many may disagree with me but for their footprint, full range class D amps are incredibly small and can sound fantastic. Depending on how many channels you want (or need) JL Audio's XD range of amps would be my go to suggestion.
Focal have some great sounding amps as to Hertz, Audison, though they many not be all that wallet friendly for some. JBL offer great sounding amps for a more reasonable price. Just stay away from your traditional halfords brands (Vibe, Edge, FLi, Fusion) and you shouldn't have many issues.
Conclusion, if you're even half considering upgrading your speakers, budget in for an amp as well, it will really wake the speakers up and without getting into the technicalities of it, will sound much better than running them off the factory amp.