You don't need a high protein pellet. Pigeons naturally only eat grains.... too much protein can be harmful to them.
Just feed a standard chicken layer pellet... together with some mixed grains.
Where my pigeons live....
My first few 3 pairs lived in a big wire dog crate each in back yard. Let out to fly every day and shut in at night. As they had babies I built them a coop. Now they have a lot and I moved house.. so then made them a big wire aviary in the garden to live in with...