Murraya paniculata, standard or mini, is not available in the UK and would not survive frost outdoors. I have one greenhouse plant grown from seed I found in Singapore.
The nearest equivalent here is the hybrid forms of CHOISYA × DEWITTEANA such as the cultivar 'AZTEC PEARL'. This is also a distant citrus relative. It is frost hardy and has very similar flowers to Murraya, although less fragrant.