Would an Amplifier be the solution

I apologize for my ignorance in the situation and will make this my last question, IF the 6-disc is placed in the 2000 SE, and the speakers are inadequate to support it, and the they cannot be easily or cheaply replaced, can an aftermarket Amplifier simply be added to the system to make them meet the demand, or is that not the problem? Would it be easiet just to buy aftermarket speakers? (for reference I would prefer to buy the stock 6-disc because I prefer the stock look, and i feel cheated because I bought my truck one year before it was available, I just didn't like the interior of the 01-04s or the exterior of the 02-04s)

You know, you can continue posting in your previous discussion instead of starting a new one...

Of course, you could add an amplifier to drive the 4-ohm speakers, but you would need one that can accept a previously-amplified source signal instead of a low-level line-in signal.
And of course aftermarket speakers are an option. Before you ask which ones, read the previous discussions here, there are plenty of options...