you should consider a carpenter/Joiner
a Multiskill trade, a builder.
look through these trades profile to establish if your local trades carry out the work you want to be done.
Ok having carried out a similar project before, this is my thoughts.
depending on the plaster repairs.... and cause of them?
I would recommend the following:
To achieve the insulation I would use thermal Plasterbourd - this will also provide a perfectly flat wall for your panelling.
now when you say panelling......?
You can use various types of timber mouldings & set out to suit the style you have in mind.
Using Instagram & Pinterest for inspiration 👀 simply search using a few key words with the obligatory hashtag #
#paneling #wallpanel #homedecor #paneling
or my preference is to use 6mm MDF cut into sections this gives an incredible
“Shaker Style” look that once painted will create an elegant focal point to any room of the house & become the talking point when family, Friends & neighbours call by!
after lockdown of course