I have a HDTV arriving next week. I currently have only SD service and plan to upgrade to HD. Would you wait until the TV arrives to upgrade the service? Or, upgrade the service so it is ready when the TV arrives? I currently have a 625 dual tuner which serves two TV's, both of which are SD only. My concern would be if the tech guy could set everything up for HD with only SD televisions. Thanks in advance for any help.