I think it all depends what exactly you want to do...
Some time ago I downloaded an App called "Forms". You import your own Google Docs created Forms and can fill them out on the iPad even when offline. Once online you can upload the filled forms.
Do you need to have the calculated values while filling the inspections I guess it doesn't work out for you. However this is a good data collection tool.
You may want to look further into numbers, though I have no idea (yet) if it is possible to protect the formulas there...