Hi Rodney,
Yep, Mitel's UC360 is a SIP only device. It doesn't connect like the other Mitel IP Phones (e.g. 5330e, 5340e type phones) those phones connect via Mitel's proprietary "MiNet Protocol". (FYI: I think the 5330e's and 5430e's can be set to SIP mode too, but I've never set that up - though I'd be curious to see it on an open source PBX like Microsoft's 3CX)
...and nope, you wouldn't see a UC360 in the drop down menu of Device Type in User and Services Configuration, you have to select UC Endpoint.
Also I got my 2nd post up prematurely as I went back in and removed the guide so that I could tweak it a bit, it should be back up now. If you follow it, you should be good to go. Hope this helps.
Thanks,
-Iron