Help making panel decision

So I am ready to raise my frame and now need to order panels. The prices seem to be rising from when I got my first quotes several months ago. I found a place that does EPS panels for reasonable money but have been told to stay away and stick with XPS panels. If I could get some advice on panels that would help. Also I have been told it is wise to put a cold roof on to protect the panels on the roof. Are there any other options?