I am used to customize UIAlertViews through the [alert setValue:someView forKey:@\"accessoryView\"] method. This creates customizable content for U
I suggest not your wasting time trying to cram additional UI into a place where isn't supposed to be. Based on the last few years of improvements, Apple will probably add a custom view in the next iOS. Until then, have a look at a framework designed to handle this exact situation without subverting any best practices: SDCAlertView
It supports alerts that imitate the native alerts on iOS 7,8,9, including handling all of the nasty edge cases around sizing, button types, rotation, etc. It does support arbitrary custom views within the alert.
I use this library in Yahoo YMPromptKit for custom push notification prompts that look exactly like iOS native. Here's another example: