fathers wish for a head stone

We lost my mom two yrs ago on Thanksgiving. She had been ill for a time but a go getter. My father is a retired vet and saved all he could to make sure all provisions were made for when she passed. 
His house was broken into and all money and collectables were stolen as well as his medals from the Airforce, and his safe was broken into. They were so heart broken.
The day of the funeral we came home to an attempted break in.  Apparently who ever was doing
 this knew we were not home that day. 
Stress levels high my father became ill and we almost lost him in January 2015.  Not only heart broken after being married for almost 60 yrs but more break ins and the stress of fixed income with nothing to fall back on and a head stone that he couldnt afford now.
I am hoping to suprise him with the cost of the head stone and maybe a little more to help cost of living. 
His fear is that he will pass and not have it up there to honor her in a way that she should be.
I hope you will help us make this possible for him.
He is 80yrs old and I dont want this to bring him down again. I want his last days here to be stress free .
I thank you all who will give. I am hoping we can get this to him before Christmas.
Thank you ,
Mitzi