I have outdoor patio that is covered and outdoor shower.  

first, if I want 2 outdoor speakers for patio, it seems I need the amp.   does the amp go INSIDE?  or can it be outside?  I assume amp needs power plug but I have that outside, curious if AMP works outside. 

second, if I also want to have music in an outside shower (this is near beach ) can I string a single outdoor speaker to the single amp that is being used for the other 2 speakers??   

any suggestions ?