i have exactly the same tank as you, (90l kent marine bio reef) this is your tank but my one has the skimmer fitted, its a lovely tank and if you choose sensibly you can have a really nice setup.
i have 2 clowns a gramma and a blue tang, then inverts 2 starfish a brittlestar 3 turbo snails 3 naserus snails a sea urchin, many corals and a pink tipped anemone, this has been running for 5 months although after reading about the success most people have i would skip the stars as they dont feed in captivity if you get the wrong species and half the lfs dont know the difference in my case i had a combination of a great lfs and luck.
i have been running sucessfully for 5 months so far with no loss of life, if your running stock setup then upgrade the heater to a 250watt (should just fit in the first compartment slanted) this will prevent the violent temperature swings that i got with the underpowered stock heater, and fit a better submersible pump to improve the flow and a power head.
other than these things the rest is personal preference really, also i would put a new set of power compacts in as they lose power over time and light is very important to a marine setup (assume you have 2 sets of pc lights and a 2 led strips, i run 1 daylight white and 1 split blue and pink.