What model of iPhone should I get?

Hi iv been thinking about getting an hour phone but because there's so many different models its hard to pick and also is it still OK to get the older versions will they still be useable even after support for them ends, can you help me out?

Well of course the best ones are the latest, the 7 or 7 Plus.

Currently the iPhone 5 through 7/7 Plus are still updated with iOS.