Contact a landscaper or tree trimming company where new construction is occurring and palms are located.
Juvenile palms (under six feet) don't transplant well since the cut roots die back to the main stalk (transplant shock ?), and mature palms need to be supported until new roots occur.
Since you are looking for stumps, the best place to look is on private land where the palms are being cleared due to new construction.
a landscaper- good idea. thanks