Hi jnmac. I think the best way is to enter the chart of account manually for the first time. Because you have to define the level of details & posting edit for each account you entered. I recommended you create a model chart of account firstly. For example business unit = MD ~ MD.100 is fixed assets, level of details = 3 (non posting). The following MD.101 is Building, LOD = 5 (posting).
Then, copy MD chart of accounts to actual business unit by using the program G09411, P0006.