I'm further minded to install a Grundfos Alpha pump, however, I'm
undecided
as to the control mechanism i.e. a flow switch as advocated by IMM in a
previous thread or to rely on the boiler stat set to 82degC as you stated.

Unfortunately, relying on the boiler stat would not meet building
regulations. You must have a flow switch, a room thermostat (in a room
without a TRV) or other similar mechanism that entirely cuts the boiler when
no heat is required.

Christian.