Contract length is exactly the same whether you buy direct or resale.
The only resort that has more than one possible contract length is OKW. It's a long story as to why; well covered in other threads on these boards. You can find both the earlier or later expiration dates via resale, with the shorter expiration more common. Buying at OKW direct now, you would get the later expiration.
For everything else, every contract at a given resort carries the same expiration date.