Xbox 360 Power Supply Issues..

Alright. Well here goes. I bought a second 360 off of eBay, it just doesn't have the power supply.

It was manufactured in November 2, 2007. It's the HDMI cable. I was curious as to which power supply I need? I'm not sure if I need the 175 Watt one or the 203 Watt one. I've also heard that the newer 360's can support either or?

Any help is great. Thanks.

From the seller:

 

I agree with the seller in trying the 175, but if you really need to be sure, I'd give microsoft a call. They can be tough, but its worth it in the end.