Factually license free radios WILL often cover around 2 1/2 miles dependent on the surroundings. A license free radio that might suit you is the Hytera TC-320 Here:
http://twowayradiosuk.co.uk/product-details/hytera/tc320lf-handset-details.htm but licensed radios such as the TC-620 will easily achieve the range you need here:
http://twowayradiosuk.co.uk/product-details/hytera/tc620-handset-details.htm
If you need to locate hundreds of handsets to choose the best 'fit' for your needs then visit
https://twowayradiosuk.co.uk which has very competitive handsets as well as offering completely free advice without any commitment from you.
They have on that site enough different radios that can suit almost every single consideration that a buyer might need to take in to account, such as warranty period, tech support and high quality of service from my experience. Hope it helps.