[Dmitry83]

So as a result of the discussion with the Seller, they've requested the replacement spring from Eibach, which will be sent to me.
I can't predict how much time it will take, but obviously will receive it in a month or so.

Meanwhile I will concentrate on shocks research.
At the moment there are only two options:
1) KW Variant 1, which I don't want due to a minimal 40mm lowering and higher price (+ I have the 2-years experience on E81, so want something other).
2) Bilstein B6

Koni did not reply to my question when they are going to launch the shocks for E84, but taking into account they have started with FSD for E83 X3 only in 2013(!), it's a long time to wait. And I am definitely not interested in FSD- only Sport Yellow. So this is not a way to go.

Lowtec does not offer anything as well as ST.

ACSchnitzer has a complete suspension setup (shocks are manufactured by Bilstein as per what I could have found out), but the price is enormous.

So for now awaiting for Bilstein B6 (B12 Pro-Kit actually) review from the local forum member- hopefully it will be installed this week.