Advise/Opinions on best wireless network product setup

Hey guys, I am getting my first desktop in a week and I want to be able to set up the fastest wireless network possible. I have a netgear rangemax right now and it doesnt have the best range or speed really. I want the very best speed and range possible (range would be secondary here).

I will have to use wireless for connecting to my desktop (which will be in another room from the internet connection).

My plan: Be able to have incredible speed from the router to the desktop AND be able to stream very good quality video from the desktop to my Xbox 360 in another room with no delays.

I am guessing I will need another router and the best possible wireless receiver for the desktop.

Price is really no object, I just want to know the dream setup really and just be done with it.

I do not fully understand all of the a/b/g/n stuff and if some knowledge of that is necessary for the advise it would help a ton if you included a little about why understanding that would be necessary or helpful.

Oh, and I will be using a laptop with this sometimes too and my internet service is the fastest "turbo" service that Comcast offers me.