One great webiste to thelp you find telephone system installers is www.telephonesystems.com. You could also search the yellowpages.
Panasonic does not manufacture office telephone systems, but they do make phones that would work well in an office.
Meridian and NEC both sell office telephone systems.
Verizon offers good office telephone systems for new york
Vonage Telephone Service and Charter Telephone Service are some of the best telephone systems you can find.
"Most office telephone systems are more than one year old. The life of the office telephone system depends on the durability of the system, the abuse it is put through, and its usage."
Resource Nation is the best site for comparing office telephone systems. It will show a large variety of systems to compare and offers expert advice on Comparing systems.
Cisco offers telephone office equipment. You can visit them at www.cisco.com
Some of the basic features that telephone office systems offer are auto-attendant, conferencing, hold music, directory services, and voicemail.
Small office telephone systems can be purchased directly from most phone companies like AT&T. Other places to try are office supply stores like Staples.
You can go to a sight specific for office telephone systems or you can go to a phone carrior such as bellsouth or you're local phone company and ask them direct.
Online search engines provide many links for information on office telephone systems. You can also find more informationation at you local electronic stores.
"There are many quality office telephone systems. Some of these systems are large while others are smaller. The larger systems are represented by companies such as Cisco and Nortel while Avaya, 3Com and Mitel are some of the smaller ones."