I agree the BGS website is quite good for advice and you can read a bit about the different breeds and think about which one might suit you. When sourcing goats I would always ask if the herd has been tested for CAE (caprine arthritis encephalitis) - As well as being good practice to test for this disease, I think it is a fairly good indicator of the care someone has for their goats, ie if they are bothered to test for CAE they are far more likely to take good care of the goats in other ways.