Not sure there is such a thing as you are asking.
The obvious solution is a quality carrier bag with some foam in it.
Can see where you are coming from. The reason why company staff get mugged on the way to the bank is because of the way they are carrying the money. If they just used a Sainsbury's carrier bag no one would know.
I have an old laptop bag you can have but it does shout "Laptop" and also has the word Laptop written on it. It's only 12" x 12" x 3" so may not be any good for today's laptops.
If you want it email me your address and you can have it for just the postage.