Alright, so, I have a 1999 TA, standard stock 10-Monsoon system. One of my rear 6.5s is blown, however I plan on getting that replaced in the next week, just using a factory speaker.

I want to get a 10" installed, and I've read up on these forums about the monsoon system. Now, I'm not looking to install anything besides the 10" sub after I've replaced my stock rear speaker.

My question is, from what I've read on these forums, it'd be better to replace the stock amp and get one that can power all of the stock speakers as well as the sub I wish to add. I've also read, though, that if you replace the amp, you have to replace the HU? Or did I misinterpret that?

I'm looking to spend in the neighborhood of 300-400$, I'm not exactly an "audiophile," I just want something that sounds good and clean. Which amp/sub would you guys here that most likely know more about all of this than I do recommend, and can anyone clarify about my question in the previous paragraph?