I will throw my opinion into the mix.
I have KW Clubsports on my E92 and I love them. I want them for my E36 as well. Its also a very easy plug and play design given that they include camber plates and arrived pre-assembled. Install was straight forward and then I had them adjusted by MRF.
I had Moton Clubsports on my 997 and while they were also a great coilover I found the speccing of spring rates ect. rather daunting.
KW CS is a great start for a dual purpose E9X M