Not an ED30 as you requested, but...
H&R makes a lower spring...we can get them here in the States.
SuperSport they're called. Mine sits from 23.88" @ front and 24" @ back with them. Dampers are Bilstein B8.
I still have the front SS's but with H&R street performance coil-over springs and adjusters in back. Pics ↓
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