Camera buying help please - Olympus PEN

I'm looking to buy an Olympus Pen for my wife. I'm not too fussed between the E-PL7 or the E-PL8 and they seem to be similarly priced anyway.

I'm naturally after the best deal possible and was wondering if it's worth buying the body and lens separately. I've found these used bodies: Used Olympus PEN E-PL8
Can anyone point me in to the right direction to buy a lens separately (preferably the 14-42mm pancake lens that seems to come as standard)?

Alternatively would anyone advise that it's not really worth going down this route and it would be better to just buy the camera and lens complete? If so where's best to look for a good deal?
Sorry, I'm a total novice in this field so please excuse my ignorance but what are the key differences between the lenses you kindly linked above and the 'pancake' lens that seems to come with the camera as standard? Olympus Pen E-PL8 with 14-42mm EZ Pancake Lens - Black

Is there anything that she wouldn't be able to do with the lenses from WEX that she would with the pancake lens?