EasyPerformance sent me a message back about the double heated seat switch. Here's what they said.

To produce a Dual Seat Heater Switch Bezel Assembly, we need two
bezels/switch assemblies to produce the one dual switch bezel/switch
assembly. Either you would need to supply us one or two switch assemblies or
we could supply one or two new old stock (NOS) seat heater switch
assemblies. We can not purchase the bezels by them selves. We can only
purchase the entire seat heater switch/bezel assembly. If we were to supply
the bezels, the price for the switches we would supply would be $65.00 each
for a total of $130.00 for the set of two. Regardless of our getting the
switch assemblies or you supplying them to us, we would charge $35.00 for
graphing the two bezels into a single dual switch bezel and modifying the
passenger switch to be compatible with the seat heater. Keep in mind, if you
were to supply the switches, we can not guarantee the color match or wear
condition between the two switch bezels. If we supply the switches, they
will be a color matched set and will look like new.

The cost per item to order a dual switch bezel from us would be as follows:

Seat Heater Switch Assemblies: $65.00 each ($130.00 for two)

Fabrication of Dual Seat Heater Switch Bezel Assembly: $35.00

Shipping & Handling: $10.00