Is there an "inventory mod" that doesn't allow cheating?
Solution 1:
NEI can be set to Recipe Mode. And if you think you'll still be too tempted to switch to cheat mode, open the file %appdata%\.minecraft\config\NEI.cfg and modify the following setting:
lockmode=0
This will make it impossible to switch to another mode ingame.
If you consider the ability to delete items (instead of having to burn them) no cheating, you could also set
lockmode=1
utility_actions=delete
to lock to utility mode, where the delete item icon is available in addition (I removed magnet, since that's already a cheat)