Radio to requirements

Not new to radio but I am not super techy so please be gently.

I work in an office in Bristol (uk) and my wife works in one about 2.5 miles (4 kilometres) from my office and I need to be able to talk with handheld walkie talkie.

We have a seperate system using Motorola GP340`s which make the trip but can only be used for security (strict) but I don’t know if they are VHF or UHF but they make the trip and work well enough between these two sites. Could anyone suggest something a bit cheaper with enough ERP to make effective comms this distance?
Look forward to your ideas.

The Motorola GP340 has several versions. The VHF and UHF versions max out at 4 watts, but there is also a low band version that can transmit at 6 watts. To find out which version you have, take off the battery and look for a label on the radio chasis. There may be something there that indicates either: VHF, UHF, UHF1, LB1, or LB2.

If you have the VHF or UHF1 version, the Motorola AXU4100 or AXV5100 would match up pretty well with it.