Hey Jay,
Most of us use Clark aftermarket boards with a few ElMod and IBU aftermarket boards used as well.
If you are using the BB system, make sure to not have it loaded during the IR combat as many of the Modelers here will frown upon BB's destroying their beautifully crafted and painted exterior details.
Best tanks for suspension are any that have an actual torsion bar suspension (Taigen PZ III & KV-1 come to mind...) Panzer IV, while the best looking tank IMHO, has probably the worst suspension of all tanks.