out of band management gear

Hi folks, I wonder if anyone has good experiences to share with out-of-band hardware? I'm looking for a good OOB hardware vendor. I need to manage my routers/switches/firewalls in a datacenter located overseas, and I'm looking to setup a good serial console server via an OOB link. I've been looking at Lantronix, OpenGear, Raritan...but they all seem to have the same basic features. I'm having trouble really differentiating them. I'm interested in analog modem, cellular options for my OOB link. Or even a secondary internet circuit either wired or wifi if the DC has that option available. Any good suggestions or experiences with a current OOB solution out there? What are you doing for your OOB management? thanks,Hank