I wouldn't touch MSY with a barge pole. If you need to warranty something (and its quite possible you will at some point; just ask Dwain), they will try to fuck you from what I've heard (read
MSY Targeted by ACCC). Like Dwain, I recommend Scorptec, they're really good when it comes to
not fucking you. They aren't cheap, though, but you pay for what you get. With that in mind, though, if you ever need to warranty something, you'll have to ship it back to them here in Victoria, which does suck.
I'd probably get a PSU with a little more wattage, if I were you (I'd recommend around 650W). What you've got will work, I think, but if you ever want to start beefing stuff up or adding more hard drives etc, you'd probably have to replace it. For example, top end graphics cards can pull 300W on their own (though you're not getting one). Also, PSUs tend to slowly lose their ability to supply watts over time, so its best to get more than you need to compensate. A stronger PSU probably won't set you back too much extra anyway. If you can get one with removable cables, that's good too, because it makes it much easier to make the inside of the case neat. PSU issues are also really hard to debug (weird shit starts happening; space-time tears), so IMO its best to avoid ever having to worry about not having enough power.