You may find that the ride insnt very nice due to a stiff spring with soft shocks, although if you have got sports suspension it should be ok. If you had got Eibach springs then you would have any problems because they lower the car yet retain the same stiffness as the original springs. Personally I dont think you need to lower your mini other then for looks. I have been on runs whereby minis with £1000 coilover suspension still havent been able to keep up with me on the bends and I have standard sports suspension plus. People with coilovers may have an outrage here but personally i think the guy just couldnt drive.
Novel over....