When I checked Summit, the Mopar shim head gaskets are special order, and cost $171.99
The inexpensive Mr Gasket is also special order, but just $25.26 each.
They do have two different bore size, 0.027" thick Cometic MLS gaskets in stock at $88.41 each.
I don't know how easy or hard it is to get parts for a big block Mopar in the EU?
Part of my thinking on the Fel-Pro kit, is it should be easier to get, but also includes most of the other gaskets and seals the owner will likely need like the valve cover gaskets, valve stem seals, plus all the extra gaskets that may be needed later like water pump and housing, timing chain cover, oil pump and oil pan, front cover seal, rear main seal, and thermostat gasket.