Moraaaaa

Hi.guys.This is moraaaaa.
Because linus LOVES Apple products very much. I want to come here for some help.I need Apple operating system to develop app.So i need buy a mac i guess.I have only used iphone, this is the only Apple product I use. I am really confused because I noticed that there are many versions of Apple computers.I won't use mac to play games, I will only use it to write code and use adobe products (ps and ai you know.).I don't want to spend too much. Because I think the Apple product itself already has too much premium. And i am not Cult.So I want to seek some advice.And please forgive my terrible english.I have about $1800.thank you！