Photoshop can handle PEF. Be sure you have the latest version Camera Raw 4.4.1
update.
May as well shoot RAW and know you have as much info as possible. I have 2TB storage for this reason!
Adobe has Bridge for viewing images but, though it has good features, it is insanely slow at some operations. I use the free version of
FastStone Image Viewer, which has batch convert and other useful features. However I will need something more powerful soon.