Hi guys...I do not have the much expertise with phone systems but I have the task of purchasing one...anyway we are a small business and after talking to the receptionist (by the way the new phone system will be at a NEW location)we basically never have more than 8 people making/receiving calls at the same time...so I guess 10 would be a safe number...I am planning on getting a hybrid phone system and I will have a 5MB data line coming from lightpath (with SLA) in which we can have SIP or PRI....I also plan on having a second "backup" data line from Cablevision (no SLA). MY question is should I go with PRI or SIP? I also want to be able to use the backup line for redundancy for the phones, so basically if the main data line from lightpath I want to use the backup data line as fail over so that we still have phones....Thanks alot!