Hi Paul,
We stock stern identical spec. Speakers as sold by rs components here
https://uk.rs-online.com/web/p/products/4318456/?grossPrice=Y&cm_mmc=UK-PLA-DS3A-_-google-_-PLA_UK_EN_Office_Supplies-_-Speakers_And_Components|Speaker_Drivers-_-PRODUCT+GROUP&matchtype=&aud-358527060186la-422422188204&gclid=EAIaIQobChMI1rHp94uO3gIV0ed3Ch1M-wzvEAQYASABEgIXfPD_BwE&gclsrc=aw.ds these match the stern ones but are slightly more powerful but similar in sound quality.*..if you use a 4ohm speaker it is best to change the wiring from parallel to series as the resistance will potentially damage your power I.c. If you want a pair £20.00 plus £4.50 postage.
Cheers Keith.
*footnote 4ohm upgraded speakers have a greater frequency range and improve the sound quality impressively...if you do not turn it up really loud the sound board will cope with the change in impedance......