Ok, let's see if I can help:
DJ - I would recommend getting the resort DJ and giving him a play list of the songs you like. The Bose system could also work but the DJ had a great system, he provided a microphone for speeches and had lights for the dance floor as well. Our group gave him requests all night and he played them all. We had an absolute blast and didn't want it to end!
Flowers - the photos they have to choose from at the resort are dated (think puffy shoulder dresses!). I brought photos of flowers that I really liked and Karla browsed through them and let me know which ones they could do that would still be included with the package. I picked one and my bouquet turned out exactly like the pic. Very pleased! I recommend sending your WC your ideas or bringing pics of your own.
Hair - I booked my appointment about 2 weeks in advance for myself, my mom and my sis to have our hair done the day of the wedding. Karla gave me the email address for the spa to book the appointment - firstname.lastname@example.org. Once we arrived at the resort, Karla told me to stop by the spa to confirm my appointment and my mom also booked herself in for a mani/pedi. Tropicalbride - I would recommend booking your wedding day appointments and your group mani/pedi session ahead of time so they'll know to have enough staff on site to accommodate you.
dfranklin - my mom and my sis had Jasmin do their hair and it was lovely! I would highly recommend her if she's still around. I did my own make up so I can't help much there. You do NOT get a discount on wedding day appointments like hair and make up however you do get discounts on other spa services. I paid $85 US to have my hair done. Mom and sis were $65-ish.
For you soon-to-be brides: DO NOT FRET! Bring copies of your emails from the WC's to your meeting when you arrive at the resort. Karla had a few details wrong when we met with her two days before our wedding but we confirmed what we wanted and she had everything arranged for us. I know it's frustrating when you don't have constant communication with your WC and you want your wedding to be #1 priority, I felt the same way. These ladies do two wedding almost every day so it's not like they're sitting in front of their computer often. This resort knows how to do weddings. I didn't even bother to go see the ceremony or reception locations until I showed up that day in my big white dress and everything was SO PERFECT!