I would get some GSP. GSP is super cool looking, grows relatively fast, and it's super hardy. Just keep it on its own island so you don't have to worry about getting it off your main rocks in the future. It's not hip, outside of huge fields of it, but F that noise it's still very cool looking.
Xenia also looks awesome. It's constantly moving. However, I pulled it all out of my main tank once I learned the little pieces it occasionally drops can grow more Xenia, thereby spreading like dandelions. So that's a risk, but probably low.
Clove polyps also are cool. I don't know if they can propagate in the water column.
Zoas are the next obvious choice. They can look amazing. You just need to be cool having a potentially lethal toxin producer sitting in water in your house in an earthquake zone.
Most of those aren't lps, but keep in mind if you just keep them on islands you can use them to mess around with coral while the tank stabilizes, and then if you want you can always pull them out and trade them for other stuff.