I have just had a cabinet built to my own specs.
basically copied the £800 arca cabinet, they very kindly put the diagrams on their website, and got someone local to give me a quote using reclaimed material for a more worn in look.
just been given the quote, £300. chuffed to bits, was expecting it to be at least the same as arca charge, if not a lttle more.
I am then putting an infared eye into the front of it costing £99 but it has 6 sensors so it will controll all my kit, and it is very tidy looking.
so maybe it is worth ringing round locally, seems cheaper to get one made to your exact spec. than buy dedicated.