Just ordered some rear Bilstein B4's from Demon Tweeks. Currently £60 each, which I think is a decent price if you can wait a few days till they are back in stock.
https://www.demon-tweeks.com/uk/bilstein-b4-gas-shock-absorber-bls19-158983/
https://www.demon-tweeks.com/uk/bilstein-b4-gas-shock-absorber-bls19-158983/
