If you're boxing, I'd strongly consider a PC.
Far greater choice in available software.

IS Boxer is the top candidate, and that is for PC's.



If you're just playing the game, I'd go with an i5 2500K system.
But if you'll be streaming and doing videos too, an i7 2600K system is about $100 extra.
The i7 has virtual cores (hyperthreading), while the i5 does not.

Get a decent motherboard for your chip.
I like Asus boards, but Gigabyte have been good too.
Everyone has a preference.

In general you want 1GB of ram for your Operating System (get a 64-bit version of Window 7).
Plus at least 1GB per client you're running.
6GB would work, but most motherboards are either multiples of 2 or of 3 slots.
So I'd go with 8GB or 12GB, to give yourself some extra ram.
Ram is very cheap.

Go with a single video card, not a pair in Crossfire/SLI.
A major consideration is the number of ports on the back of it, determining how many monitors you can use.
Mine (GTX 570) has two DVI ports and an HDMI port, so in theory I could run three monitors but am using two.

Strongly consider an SSD (solid state drive) for your gaming folder.
Doesn't have to be fancy, but its a major improvement in your play.

There are plenty of virtually silent after-market coolers for your system/CPU.
You could even go with a water cooled system, which is less noise.

Browsing the technical forum, would have more insight than I can give you.