Pelican makes a laptop case, maybe several sizes. The one I have is big enough for my 17" MacBook Pro so it should fit most laptops except certain gaming ones. It has foam you cut to the exact shape of your laptop and will absorb bumps and such, also it's waterproof unless you cut into it to create a mount for the bike or something. It comes with a strap you can hang over your shoulder but it will hurt as it swings around and hits you going over bumps and around corners.

I would say that if OP has spent enough on the laptop to be that concerned with its well being there's a good chance it does have an SSD already, but I wouldn't wager on it...