Your best bet would be to use a Smart Object.
- Open your Layers palette (Window > Layers or F7);
- Select the layers containing your objects in the Layers palette;
- right-click and choose Convert to Smart Object;
- Do your transformation / rotation with the Smart Object.
When creating a Smart Object, you essentially nest one
.psd file in another. The object behaves as a single layer, allowing you to do everything you'd do to a single layer. It is, however, still editable: double click the Smart Object layer thumbnail and it will open as a separate file in a new window. This allows you to edit the contents of the Object. If you Save and close the object, it will update in the parent file.