Caarrie is right, manually downloading the updates may not be feasible at this point in time. However, you could also install a client on the PC with a better connection and update it every time a new version appears, then zip it up, and copy over the version you have installed on the PC with 56k connection. Please note this is not a supported way of updating and it will may break the install on major release cycles, so always keep a backup. Your logs, etc are stored in a different folder, so they should not be affected in any way.