Looking for a good recipe to cover a grooms cake. Will have choc buttercream piping decor on it and needs to stand up well.

Looking for a good strawberry mousse filling as well. MY SIL wants it for filling for the grooms cake and I've never heard of it! Have found a couple of different recipes but again, its going to have to hold up overnight and everything I've found so far shows lots of whipped cream! I don't want my layers to squash together!

THanks!!!