Hey mate
I do indeed, It sounds like you've got the majority of what you need. Really depends what you want out of it though. If all your speakers and your sub are powered (meaning they have inbuilt amps) then you won't need the Crowns. If they're passive boxes then you will definitely need the amps and most likely a crossover too so that you're not sending the sub frequencies to the yamaha's which means they won't have to work as hard. If you're gonna use this system to DJ parties/weddings etc then you'll probably want a mic of some sort and you're going to need a small mixing desk too (nothing too fancy, although some will come with a built in crossover and sub output which is handy). If you're not running a mic and don't need to run anything besides the laptop you could get a stereo DI Box which would take the laptops signal and convert it to the correct level needed for the amps, can get ones which are built specifically for pc's and will take an output from one of your USB slots.
