I'm not 100% sure what all is entailed with what you want, i just glanced at your posts, but we support lots of our customers over the net through VNC (free / easy) and to deal with rotating IPS (not to mention "their IT specialists) we use http://www.NO-IP.com
It's a free service that doads a client to a host, then sends requests ever X interval to check the ip's address against what the server has. If they don't match, it updates itself and we always connect. Nice, free, easy program. They offer paid, more in depth services as well as different domains, we use no-ip.biz for all of our support.