Something to consider would be to apply a wood veneer over a steel case, That would take care of your grounding and heat issues. Finding a strong enough glue to hold the veneer to the steel/plastic parts of the case might be a challenge but you can still sand it up and put a nice stain on it. Veneer can be cut with a good razor blade for tracing out around the fan vents. Of course if you get a case with a black mesh in the front for the intake fans, I'd leave that part on and apply the veneer around it