Try a Platygyra i have bought several over the years. Started out like a postage stamp but got more dome shaped as it got larger. My favorite i had was neon green center with brown coralite scribbling. Still have several, they seem to grow slower than other in favia family
Ive had a few Platygyra and they seem to take a while to start to dome in shape, I eventually just found me a nice round live rock mounted it and within a year it started to take shape. The person I sold it to about 3 years ago said its the size of a volleyball now!