I need a little information and was hoping one of you guys could help. My wife has a business with an older Inter-Tel IMX 612/1224/2460 phone system that came with the business. The phones are Inter-Tel 660.7900's. She is having issues with a couple of the phones and has asked to find some replacements for them. I looked around and found some refurbished ones of the same model online, but I have a few questions. Will any Inter-tel IMX phone work with the system or just certain ones? Also, I'm assuming the phones will be simply plug and play replacements and not require any programming, correct? Are there any new phones that will work with it or am I limited to refurbished phones?

Now, what they'd really like to do is prop up this old system a little while until they can replace it with a more modern system. The current system is pretty basic, just controls 3 lines plus a WATTS line, and plays background music for calls on hold. They'd like a system that added caller ID & voicemail. There are only 3 employees, so it doesn't have to be anything elaborate. What are some economical options we should look at? Thanks for your time.