I would like to kindly recommend that you not get an anemone.
They are very hard to keep alive and healthy, they move around trying to find better light, knocking things over in the process, they often get sucked into powerheads, and they have very specific lighting and food requirements. Anemones in the wild live for a vast number of years. Anemones in tanks generally last less than a year, often just a few months, about the time it takes for them to finish dying, a process that often has started before they are purchased.
I wouldn't go quiet as far as shirley, however that said there are a few things I would recommend.
1. Make sure you tank is ready...."has it been running a year without any mystery deaths?"
2. Is the lighting enough I would say 250mh is going to be needed for tank depths 24" and shorter.
3. Is the only reason you are getting an anemone for the clown? If so get something different. Only get the anemone if you are interested in them themselves.
Lastly and most importantly. After all the conditions are stable and have been for some time (maybe a year) then find a CLONE. Either someone who has one that has split or an online vender that sells clones. At least this way you aren't pulling one out of the wild, and its already acclimated to MH style lighting.
Just my 2 cents. Keeping one is something that really needs to be thought long and hard about. The mortality rate is very high, and they are tough. Like 99% of what we keep in our tanks it probably should be left in the wild. The question becomes how close can we get the environment, and how happy will this creature be compared to in the wild. (example, your clowns should be happier NO PREDATORS!)
I would also encourage you to not get an anemone. We once had a percula that hosted with a Maxi-Jet 1200. They'll find something if they need something. Our gold-stripe maroon hasn't felt the need, although it loves to swim through the pulsing xenia.
Ritteri (Heteractis magnifica) are the best choice but are very difficult to keep. And they usually end up attaching in a place you don't want them to as well. Like the "foot" on the front glass wall of the tank, or in a corner next to a return outlet.
Unless you are very serious about this task, do not get an anemone.
Thanks for all the input we had a anemone years ago in a 55 he laste dthrough everything (condy) well atleast til the great ice storm of 92 i think and we were without power for many many days. We will more than likely not get a anemone for this tank but will for another later down the road. Thank you all very much I did get a cool surprise on my LR i just got a little featherduster just poped out and said hello to me a few minutes ago I thought I was seeing things but he's really there my wife doesnt believe me though
Attached is a pic of my marron clown and anemone. I have had the anemone for about 6 months or better. I have also read that they are hard to keep alive. I do nothing for my anemone, in fact my lights are only running about 5 hours a day with only having 80w's over the tank (90g). My clown took to it right away, it was my brothers and his clown died so he gave it to me. I never feed it but I do see my clown feeding it a few times a month.
Of the anemones, the BTA and the cLTA are the easiest to keep from my experience. I've founld the following to hold for them in my tanks.
This is what I've seen for these two:
1 - temperature is important. They do best from 78 - 80 F. Above 83 or 84 they can go down hill rapidly.
2 - They have done better under moderate light rather than very bright light. The best LTA I have is in about a 60 gallon tank with 2 65W PCs over it.
3 - They have done significantly better where 2 currents cross or just to the side of where the currents cross. In the tank with the LTA it has 2 1140 PHs. It is just off where the currents from these two cross.
4 - I feed it once aq week with: Fresh Fish, Scallops, Shrimp, or Squid.
I have an LTA and a Number of BTAs that are 2 years old and cloning and/or over 14 inches across.