You may want to keep an eye out for deployment schedules. Given your large group and need for multiple cabins, it may be to your advantage to book as soon as schedules are released for the best choice of cabins and, probably, best price. Itineraries for July 2025 will be released well before November 2024, if I understand your planning correctly. Also, going through a travel agent could reduce your workload tremendously on this and net you some perks as well, such as onboard credit.
i do all trip planning for my husband and me, I actually love “getting to know” a place before we visit through research and online exploration. This site is a wonderful resource.