Text overlay on scene with moving camera/mesh.

I am modelling an engine and currently have the animations of the moving parts, rotating the engine and zooming functionality working.

I am now adding the functionality to show temperatures & fluid flow rates in specific parts of the engine. I would like to show the text as an overlay with the text in a bubble that points to the part. I was originally thinking of using 3D Text but am leaning towards the GUI Text implementation. I also want to keep the text upright if the engine is rotated sideways/upside down.

Using a GUI Text overlay, is it possible to move the text with the specific part (with the speech bubble)? This implementation must also be able to work with the Oculus Rift DK2.

Any thoughts?

 

I am currently using v4.5....is there a better way to do this with the new UI features in 4.6?