I have never roasted a chicken in the crockpot. If you do try this, don't add water. It will be a simmered or boiled chicken, not roasted. From what I have read, it will take a LONG time (10 hours is what I read). However, it may be that you don't have an oven, in which case, I reckon it can be done in a crockpot. I don't see how you can make stock from this same chicken unless you use the giblets and bones from the already roasted chicken.
Likely, there is some trick that I am not aware of for this.
Someone will be along shortly to help. There is a tremendous number of resourceful folks here.