 Re: whether
If has three uses - it can express : a) a condition, b) the idea "given that X is true" or c) the concept possibly yes, possibly no
Whether doesn't just mean if - it means if or not. So it can only be used in contexts where there is a yes or no possibility - ie replacing if when it is used with its third use. Some examples :
I don't know if/whether I shall go to the conference (possibly yes, possibly no)
He asked me if/whether I liked cats (possibly yes, possibly no)
In your context there is no yes/no possibility. Here if expresses a condition - not a yes/no alternative, and therefore whether cannot be used. Notice that it's a hypothetical condition (currently the tours are not fully equipped) and so the second form of the verb should be used :
It would be better if these were fully equipped tours
Other examples where if expresses a condition and therefore can't be replaced by whether include :
If the phone rings while I'm gone, would someone answer it please?
If I hadn't missed the plane, I'd be on the beach now!
And some where it means Given that X is true... :
If you saw him, why didn't you tell him about the meeting?
If you knew about it, you should have told me.
etc |