I was wondering which Yates fungicide would be suitable to use on buffalo lams for brown patch and dollar spo

Try 'Yates Mancozeb Plus Garden Fungicide & Miticide'. It is a multi-purpose, dual-active formulation combining the benefits of mancozeb and wettable sulfur. Both actives have a contact fungicidal action, helping to control and prevent the entry and spread of a range of common fungal diseases. 

Hope this helps and happy gardening :)