marines scream expensive, to do it properly, spend the money, that's the best key.
As much water volume that you can get is the key to stability, the slightest fluctuations in marines can cause systems to crash.
Lights, up to you, what do you want to keep, what colour temperature range do you like, do you want that shimmer effect etc. LEDs are the way these days, several HOT5s are also popular but costly replacements cost, halides are seemingly sounding to become outdated, due to dearer running costs and expensive annual bulb replacement.
Skimmers help remove certain soluble wastes and products that simple biological or mechanical filtration cant remove, I have seen stunning set ups with out them thrive and yeah the crappest looking tankw with them. QUlaity effectively tuned skimmer will do you wonders and work really well. For nano systmes such as yours I have used Tunze Nano skim 9002 - easily tuned, no micro bubbles and skimmed a cup of gunk weekly! But just cause you have a skimmer doesn't mean you can let water changes slide. youll still need to replace essential trace elements for coral and invert well being, as well as maintaining low phosphates and nitrates in the system.
Water movement, ppl skimp on this greatly. Replicate the ocean, as random and quality flow as you can.
If I where to do another marine aquarium that size, id go A vortech MP10, and have it on a reef crest mode or lagoon mood, or the short pulse (movement of these little things are awesome - also super small pumps so take up minimal room in the tank).
Id recommend turning the water over minimum 20-30 times an hour, especially if our wanting to keep more temperamental coral species such as acroporas and many other sps.
Just my 2 sense - look on the nanoreef.com website, mainly American, but my word the set ups and that on there are stunning, that site is based to advanced nano reef keepers with very high class set ups, as well as simple yet stunning systems.
Good luck and enjoy the journey, I like the tank you got!