need help with sirius radio purchase

[sublime]

i gotta get one for my step dad for my mom (meaning i am getting for her to give to him). while i am at it, i figured i should get one for myself. anyways, what do i need to buy? i suppose the best thing to do is get a unit that is good for the car and the home. do these need to be installed etc.....? what about subscriptions, do they come in different shapes and sizes? im sure he wants the NFL thing etc....

tia