Narlin,
The user name and password you were asked for, was just for the PTC website. You can just sign up for it, with no charge.
Mathcad 14.0 is what you will receive, and you will get information to get 14.0 m011 when you purchase it from the same download site, where Mathcad 13.1 is posted. PTC is still distributing 14.0 but upgrading purchasers to m011. However for releases beyond m011, you need to purchase maintenance.
The node-locked license is the best deal for users who only want a license for single use, because it lets you install Mathcad 14 on two computers, comes with free technical support, and access to maintenance. I suggest you wait until a bit later this spring to purchase that.
Mona