Need Advice - Create a Site-To-Site VPN Tunnel

[Ultragc]

Hi All,

Need some suggestion of setting up a site-to-site VPN between two offices. Here's what the two office have now:

Office-A
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Carrier = Spectrum Cable
Computer = 4-6
Phone Line = 1
Fax Line = 1

Office-B
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Carrier = Verizon Fios
Computer = 4-6
Phone Line = 1
Fax Line = 1

Goals
---------
1. Create a Site-To-Site tunnel between the two sites.
2. Re-configure the phone in such a way that if someone calls the Office-A, it also rights on Office-B. This is so that receptionist on both offices can help one another if needed. Don't have a problem putting two separate one in each office.

Given the above, here are my questions:

1. Do I need to replace the existing routers from the carriers?
2. Which router (reliable and easy to setup) do you recommend?
3. Do I need static IP on both offices?
4. For the phone, does it make sense to to VOIP in each office and which company do you recommend?
5. Any better approach?

Thanks in advance.