Ill preface by saying I know absolutely nothing about radios, but I work for a business that needs to get a hold of about five radios for long-range communication with our two satellite branchs all within about 3-4 miles. I was wondering if anybody had any suggestions and especially if being in the downtown area with skyscrapers would hinder any signals. Thanks in advance.
Radio signals will not talk through buildings. The signal will bounce, depending upon the frequency they are on, somewhat but not for 3-4 miles. The only way you could get good, reliable communications is to install an repeater/antenna system on top of one of those tall buildings.
If you want to communicate with satellite offices and they are connected to the same office network, you may want to consider investing in Radio over IP (RoIP) radios. They operate as two way radios but connect through a wi-fi network.
Icom just launched the IP100H. It’s a bit pricey but may what you need.
You can hear a full discussion on the Icom IP100H system on The Two Way Radio Show Podcast TWRS-82. It explains how the IP radio system works.