I think the plain one is probably fine. If you're planning on adopting more PBX platforms, best to keep it generic. I've had good luck in the past just going to Fiverr and having someone create a logo for me. Pretty quick, and quality is good in my experience. The logo I have now was from a local guy that did my website too, he is absolutely awesome. He costs a good bit more than Fiverr, but is still very reasonably priced.
Didn't there used to be a big UNOFFICIAL banner at the top of the forum? Maybe it goes away when you log in or something..? Might be a good idea to put that back.