I'd go online and search CKD Galbraith, Retties, Bell Ingram, McCrae & McCrae, plus ANM for the far north, there is also primelocation and similar which you can search for 'land' tho you get plots as well as actual land and farms/smallholdings for sale.
I'm selling up in Fife (with McCrae & McCrae) and those are where I look for possible new land to move to (except ANM as I'm central belt focused not north east).
Good luck