OK I get it now. Of course tbskoglund is correct that the Suhr unit will work.
The H90 allows you to specify the control change command(s) transmitted by up to 2 exp pedals or up to 6 aux switches. So in this case you can dedicate an aux switch or two for amp switching and assign a proper control change command or two as specified in the chart provided by Suhr.
Then, if you want some H90 parameters to change along with the amp channel, you can assign them to the same aux switch(es).
Looks good to me.
