Yes they are the same device. Buzz is the internal name for the Wildfire by HTC. (All devices have such a name - Atleast HTC ones. More examples - Desire is called Bravo, Desire HD is called Ace, Desire Z is called Vision, Desire S is called Saga, Sensation is called Pyramid etc etc)
For modifications, you will have to root your phone, which is possible only if it is on Official 2.1 release. Official 2.2.1 cannot be rooted by any software yet, and the link below is not applicable in that case.
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