Well, one thing you should be aware of is that once you add an anemone, it becomes an anemone tank. In other words, the entire tank is at its mercy. If it decides to move, more often than not, it will sting and kill corals. There may be corals that sting and kill it (several come to mind). Either way, it can end up messy, expensive, and unfair to any of the animals. If you decide to get an anemone, be prepared to do what it takes to keep one, which means keeping things out of its path and minimizing the likelihood that it will move by providing the ideal environment. Healthy anemones only need a handful of things to be "happy."
This includes: 1) adequate water quality--nitrate and phosphate aren't an issue, but pH, alkalinity, salinity, temperature, etc. are the big things you need to consider. Make sure they are within the acceptable ranges. 2) Substrate--anemones need the appropriate stimuli from their preferred substrate to do much of anything. The best water quality in the world won't help this. 3) Water motion--most species prefer a moderate amount, which is enough to flush wastes, etc. If it causes the anemone to flap over itself, chances are you have too much. If the amount of circulation is diffused, but strong, this is also acceptable and makes for good results, IME. 4) Food--they absolutely should be fed for optimal health. Some species seem to be able to rely on zooxanthellae a bit more, but still do better with added food. I recommend a minimum of 2x per week and a max of 4x per week (which turns to about every other day. Do not feed more often than this). Lastly, 5) light--not quite as important, IME, as the others, but still necessary. Good light will be required to keep them in adequate condition. It should be bright, but some of the recommendations of blasting them with light (minus, probably, two species) isn't really that necessary.
If you can satisfy all of this, you are one step closer to keeping an anemone successfully and with as little grief as possible. That being said, as far as my view goes, if you plan on having an anemone in there, don't count on having too many corals. Some anemones rapidly split, quickly overwhelming a tank unless you relocate the clones. Other species simply become giants. There's only one species I would recommend and that is Entacmaea quadricolor (aka bulbed-tip anemone). Keep in mind that this species can either stay small and split frequently or grow very large. They are also more of a wanderer than many of the other species, especially before a split. If it were me and I wanted a tank of that size filled with corals, I'd opt out on the anemone. But if you want an anemone in that tank, again, that's the only one I'd recommend and be prepared to relocate (or else lose) corals, at least in the beginning. Once you are familiar with the anemone and it settles more permanently (hopefully), you could potentially try to place some small corals on the perimeter. That's more at your own risk, though, in a tank of that size. JME.