Cut springs are ok. My fronts are cut... and ride just fine. But I wouldn't call them a proper solution still. There's also a method in that madness too. They must also remain captive to pass an mot..
Rally will require a deep pocket I'm afraid.
A cheapo coilover set and correct springs are £250. They should see you right for all situations tarmac rally, autotest, autosolo. Except forest rally you're looking around £1k