Solar span panels for the ceiling???

Hi,
We have had some fab plans drawn for our new build in Perth- it's very exciting.
We are going to use solar span for the skillion roof as it will give us good sized eave's and insulation .
I am wondering if any one has used this product. The costing for the new build only include ceilings in some rooms but not others.Does the solar span look ugly from the inside or should we put ceilings through out. We are trying to build sustainably but I do still care about aesthetics.
Also how does the electrician fit lights etc without roof space?
Thanks in advance for your thoughts and ideas - its our first new build and all views appreciated