The North West names are best for pronunciation tests - and the Welsh ones

Absolutely.
Though there are a few from further south and east that are also a challenge.
For example Aberuthven, Alford, Alves, Athelstaneford, Baledgarno, Drumelzier, Dumyat, Friockheim, Glamis, Kilconquhar, Kingussie, Maryculter, Milngavie, Peterculter, Rothes, Strachan, Strathaven, Tomintoul among others.