I am doing a similar configuration and do it a bit differently to cover power failures.
- Server that auto reboots on power failure and power restore - I set this in BIOS
- UPS that auto shuts system when few mins left of battery and restarts
If the power is lost for lets say 1 hour the server starts back up after seeing AC available and the automation agents restart
On the DNS question, are you looking to have your network available on the outside using DNS if your router changes IP address once in a while ?
I use dydns, but the IP rarely changes for me ( I have fairpoint)
http://www.dyndns.com/services/dns/dyndns/
jeff