There are patch panels that replace that part of the door, inside and out and from what I recall they go up far enough to get all your damage. Of course, there's no way of telling the condition of the rest of the door but it looks pretty fixable.
Yes, there are plenty of doors out there but if you can fix yours you'll eliminate all the fitting headaches or replacing the doors. They all "fit" but if you want replacements to fit well, you might be in for some work, especially with the gaps.
