I don’t know the Derby area but you don’t need a lifted disco or sump protection. If a vehicle is lifted, the height under the axle and diffs is the same unless you fit taller tyres. Much better for greenlaning is a decent set of At tyres, recovery points front and rear, decent recovery kit and spares and not going alone. Also doing research to ensure your route is legal.
Let us know how your laning goes and add some pics!