Hi guys

I'm looking to buy a speaker setup, by which i mean:
-Main set of speakers
-Amplifier
-Subwoofer

I have just started at university and i am really looking to blow all the other people on campus away, to the extent that they can't hear there own music because mine is so loud.

From what i have read, i think for the speakers i want to buy some B&W 685's, and i was thinking about importing a velodyne impact 12 subwoofer from America, but i'm stuck on what to buy for an amplifier. I have been looking into arcam a lot, but i get confused because i don't understand the difference between a power amplifier and an amplifier....do i need both? The problem i face is that i don't have a great deal of knowledge on the subject of good brands, or anything to do with speakers really...so if anyone could help me out with recommendations as to what is good and what isn't. As it stands i'm open to change on anything except for the speakers, i'm a devoted fan to B&W.

Thanks - Jack