Cat 1, 2, and 3 Suites are so popular that people fax requests to Inventory Control years in advance. I just got a call that my request for a Cat 1 was available for a August 2006 cruise. While on the phone I was surprised to find out that there are requests as far out as 2021.
The bottom line is that if you really want a suite fax a request as soon as possible. The price of the suite is an issue that you can deal with later "if" your request is available.