We need to know a few things....how much power are you starting with? 24-36 V is only part of the answer; the other part is how much current or power is available on the input? Then you need to decide on how much current you need for each rail. With the numbers you have listed above your worst case power needs are 9.5W output which would require about 10.6W of input power...this allows for 90% efficiency which is attainable. However if you can start with more power then you dont need to be as efficient.