Aloha From the Big Island, First of all Congratulations on your 10th Anniversary and hope you will enjoy ur visit to the Big Island. I can say, the rental agencies here do have jeeps for rent but can't guarantee they will be available when u get here so you need to reserve asap. But also just wanted to mention that rental agencies here restrict rental vehicles from going on the saddle road and also the summit of Mauna Kea and also Waipio Valley for safety reasons. But I've seen rented cars on those roads. At your own Risk! Good Luck and enjoy the islands.