Noob trying to build his first Htpc

I'm a newbie at this and i need help on what i should buy so i dont buy too much and stuff i don't need. Im looking to build my first htpc and i will be using it for movie rips which includes both sd and hd rips. I have a ps3 so i dont need a bluray drive for my htpc but i will need a dvd drive to load my software. I also will be using it for game console emulators and will be using xbmc as my media player. I know that i want atleast 1tb but will prob be getting 2tb. is ssd really necessary for the windows 7? or can i just store it on the hdd? I will also use the internet every so often to stream tv offline so a motherboard with wifi would be a plus. If the motherboard has hdmi out already on it will hd audio pass through it also or will i need a new sound card? lastly i already have a copy of windows 7 32bit now i know there is a 64bit but i dont know the difference between the two, will the 32bit version work for what i am going to be using the computer for? Any help would be great! Thanks!

Bill