The question is a matter of preference; how would you like to sound — formal or familiar(colloquial) and how would you regard the word "than", a preposition or conjunction. However, in the instant examples, since the suggestion is to retain nouns we can bypass case related issue.
Before answering the questions I would like cite a simple example to make the issue simpler.
He is better than me in English
(informal use but common; than - a
He is better than I am in English ( formal
as well as accepted; than - a conjunction)
He is better than I in English. (too
formal to be accepted; 'than' - a conjunction)
If we regard THAN a preposition, both of them are correct and if a conjunction, phrasal or clausal structure is necessary.