Need advice before submitting iPhone app

[Richard Miller]

I'm on the verge of submitting an iPhone/iPad app. All features are 
working, including in-app purchasing. This app has 3 versions: free, 
standard version, and a premium version.

I want to take advantage of promoting the app by offering free promo 
codes to reviewers. But I believe those codes can only be used to obtain 
a given app (whatever version it might be), but cannot be used to unlock 
features through in-app processes. Seems to me the only way around this 
is to submit to Apple 3 separate versions of my app:

- Free version, containing in-app purchase options to upgrade
- Standard version, containing an in-app purchase option to upgrade to 
the Premium version
- Premium version

With this approach, I can give reviewers promo codes for the Premium 
version.

Is this the best way to go?

Thanks.
Richard Miller