Most vets recommend the AlphaTrak pet meter because it gives results very close to what their clinic equipment gives. However, the test strips are very expensive. I believe Freestyle Lite meters and strips are available in the UK. Many use the Freestyle Lite strips in the AlphaTrak meter and get BG results that are quite close to what AlphaTrak strips give. The FS strips are significantly cheaper.
UK members can advise you on what other meters are available.