It depends on what you want to use them for. A lot of two-way radios are designed with specific tasks/uses in mind, so it depends greatly on what you need them to do.
If your application is largely workplace-orientated, then a two-way business radio will likely work best. A good all-rounder, two way business radios (available from any manufacturer), can be used for increasing safety and security levels, relaying messages and services to clients quickly and efficiently, improving employee communication and much more besides.
In addition, modern radio systems are highly customizable, that way they can better suit your business needs. You can tailor them to your workforce, customer-base, or working environment. The following is taken from IcomUK.co.uk,
"Two-way business radio is a very flexible form of communication. It can provide simple one to one communication between a small group of users or increase the number of channels so you could have one channel for everyone, one channel for management, one channel for security, one channel for cleaning and so on. You can use each channel like an intercom system that lets you call individual people or groups instead of broadcasting a message to everyone. Some radios have scanning capability so your radios will only pick up conversation for the channels you have programmed. here but security monitoring via GPS or CCTV or coverage between groups over a wide geographical area using the internet".
Two-way radios are also exceptionally easy to use. Training your staff to use them takes almost no time at all and their user-friendliness is a great 'plus point' during emergency situations.
Two way radios are also far better suited for business use than mobile phones. This list is also taken from the Icom site.
When you want to call someone on a mobile phone at a minimum you have to press a speed dial button and wait for connection. Between the dialing and the time delay of the person on the other end answering, some time can go by (if they answer at all). With a two-way radio you simply press a button and start talking. In an emergency situation, this speed could be critical.
You can talk to multiple users at once.
2wayradionline.co.uk provides radios with no monthly contract. You never have to worry about exceeding your allotted time like you would do with a mobile phone.
Icom radios are built to military specification which means that they will work in wet environment or even after they are dropped on concrete. Most mobile phone are not built to this standard.
Two way radios continue to work in natural disasters or major security incidents. Even if mobile phones do work, the mobile phone tower can get overloaded with everyone trying to make calls so your call may not go through.
Two way radios stay on site at the end of the day so can be used by shift or night workers.
There may be places in your business where mobile phones don't work. Two way radios can reach all areas of your business, when repeaters are installed.
Two-way radios that are designed for business purposes are probably your best option (in this instance, at least). Depending on the size and scale of your business, it may be wise to hire a professional to help you set up your network.