I have kept anemones for more than 20 years.
In my experience while a mature tank (at least 6 months fully stable) is a better starting point, the most important needs of the Nem, are as follows:
1. Light. Nems love their light, it's their food and they will move towards the PAR they need to continue the photosynthetic process. Never move the NEM, they do not like this at all and damage of the food can be fatal. In addition, BTA will attach to the rock whereas LTA will go to the sand, not always, but mostly.
2. Flow. Nems need a low to moderate flow in which their tentacles are gently waving. This both brings them food and keeps,them clean
3. Water. Nems need stability in water conditions. They hate change and may move because of it. So,water conditions must be excellent and replication of NSW parameters is essential.
4. Supplemental Feedings. Nems derive 75% of their nutriiton requirements directly from photosynthesis of the light. They will survive well on just light. That being said, it's OK to squirt some frozen brine or Mysis once every two weeks. You can actually kill a Nem by feeding to much too often. Digestion is quite long. And if ya think, not natural that a hunk of fish or shrimp drops in every day.
In a 34g, which is the absolute minimum I would use, I reccomend the BTA, you can find some real colourful ones of rose, green or a mix.
I have been most succesful with the BTA and I like them better than the LTA because their tentacles are shorter so they use less space.
If you are satisfied you can provide, 1,2 and 3, you could try the BTA, you may even be lucky enough for it to host the clown. If you clown accepts it, it will also feed the nem, as well as have a safe place to rest.
Good luck, that's my two cents.