I'm most likely the guy who told you that you need an alternator in your other thread. If you were to run a true 2,000 watts, you will suffer severe voltage drop which does not make amps very happy. I mean, make sure to get a good AGM battery under the hood and do the Big 3 (don't connect to engine block. Connect to alternator case, fyi).
Take my advice for what it's worth. I cut my teeth in car audio back in 1998, when lower powered, higher efficiency setups were the norm. I was hammering off of a bridged 2 channel Phoenix Gold amp making only 300 watts. It's all in the install. I've since gotten with the times to some extent. However, it's common that someone here would love the fact that a sub can TAKE over 1500 watts of power, but I would be very sad that a sub would NEED that much power to shine. I would be even more sad that said system would require me to come off an additional $400 so it could all run properly and safely. It's all personal preference.