Okay, first things first: What brew length? I presume ten US gallons from the amounts.
Second, Cara-Pils is used in many extract batches to promote body and foam. You don't need it in an all-grain recipe; you know how to mash, so you can tweak the mash procedure to give you what Cara-Pils provides. Extract brewers can't do that, so Cara-Pils comes in handy for them.
Third, 40L Crystal will probably not give you all the caramel/toffee notes you want. I advise a spectrum of Crystal malts, in respectively lesser doses: 40L, 60L, 90L.