Randi - I believe that it's a good choice you made to have Fister cremated. I have done this with most of my RB cats and dogs, as I too plan to be cremated and take them all with me when I am scattered. They all had "private" cremations, as I wanted only their remains and not that of other pets. If you don't care for the vessel that they put him in, there are many places on line that you can purchase pet cremation urns - just Google it.
My heart still breaks knowing what you are going thru right now. You will find the strength to get thru it and move on (tho differently), in time. Fister will always be in your heart, and that can never be taken away from you.