Do I need Xcode (and a Mac) to develop an Ionic app for iOS?

The are some points you need to know.

You need a Mac to create a Cordova vesion of you App?

Answer: Theoretically no, because Phonegap (Adobes Cordova) has remote Builders that you can use to create a package of you App for IOS. But, this remote service is paid.

So I should use Adobe Phonegap remote builder?

Answer: I would not use. A remote automatically builder will never be as good as you control the actions of what is being created or maipulated on your App.

So it's better to buy a mac?

Answer: Yes.

I will need an Iphone or Ipad device too?

Answer: No. As mentioned before, you could test your App using XCode emulator (wich include Iphones, Ipads and more). Only buy an IPhone if you want to be sure that all features of your App is working (given that an Emulator will never be a real device).

Good alternative: You could create a Mac Virtual Machine and try to develop through that (if your Windows Machine is really good). The problem: It will be very difficult to test your App with a real IOS device using the virtual machine. We will basically work with XCode emulators.

Yes, also you will need an apple developer account, and probable and iPhone / iPad for testing

No! You can develop apps using Ionic Framework for Cordova/Phonegap, altough in order to publish the app on the AppStore you will need an Apple developer account.

@Del - No physical device is needed for testing an app. You can use the device simulator in xCode.