There is a company called Biodex. 1-800-224-6339 You can call them and they will send you their catalog. They sell night splints for $45. The more expensive ones from the doc or other companies may be better--I don't know--I have nothing to compare it to. I did buy the Biodex night splints and have used them for a few nights. I still have the morning pain in my heel when I get up, but some people find the night splints helpful.
I was told by someone that it is not a good idea to immobilize your legs all night so I don't know what to think. I don't want to create problems in my knees and legs by wearing the night splints.