How much do you want to spend? Tricker's has the Chepstow
. Edward Green has the Gresham. John Lobb Paris has the Jodphur. Crockett & Jones has the Quorn
. Ben Silver also carries this boot, and I've seen it in dark brown suede at Polo, although it appears to be made more to Handgrade standards than the regular Quorn would be (channelled sole, etc.). JM Weston has a version, although I can't find the catalogue right now to get you the reference number. Alfred Sargent has the Childrey
and a couple of other models. There are probably other options, too, but that's a good start.