Please advise for restoring Proac EBS

Hi all, I want to restore my father-in-law's pair of ProAc E.B.S. I tried to find the 8ohm version of the ATC SP75-234 woofers but I could not find it for sale on the market. If some one can help me the would be great or if I replace them with a another brand, which one is perfectly matching side and tech data? Please advise with thanks