Hi Eddie and welcome!
I have the Max S 650 LED 2016 and you can see it on my tank thread under the Red Sea Max owners club.
As far as a review goes they are simply stunning. No wires or tubes hanging out like a science experiment just a beautiful piece of furniture in your home with a living reef inside it. They are plug and play other than no heaters/chillers. They are certainly not cheap, but you get what you pay for as far as build quality, glass etc etc.
Yes you can change the skimmer if you want, I did eventually as I learned in the hobby, but the C Skim is perfectly acceptable and works fine.
As far as the chiler is concerned, in reality were you are based, you will probably need to get one, but I would maybe wait and see as you can add it afterwards if needed. Even if you had AC, what happens if it fails when your away and the tank temp increases? I have a friend who had this happen and it wiped out his Max S 400 tank.
I'm based in the UK and the normal room temp is around 18-20c but the tank runs at around 25.5 to 26.8c roughly just from the pumps, lights etc. In our summers, Im borderline needing one and i have researched it ready and I can get next day delivery. I will get the Teco 1000 if and when I need it. Not the cheapest but I believe one of the best from what I've read.
I've spoken to my London based LFS on chillers and although they sell them, they told me to only get one if I absolutely needed it due to the noise, heat expelled etc etc. I also have the option of adding large bottles of frozen RO water to cool it if needed as it may be only a few weeks a year temps get to very high levels.
Anyway don't hesitate to ask if you need any help etc
Best wishes