Seiryu and Ming are nice but $$$. They also alter water parameters and I'm not much of a fan.
The jagged rocks are commonly sold as "lace rock" in pet stores and are really just formerly live rock. The pieces I have are all well-cleaned and have been used previously by me in sensitive shrimp tanks, so I know they won't alter parameters. Maybe not the nicest-looking stones around but I enjoy the nooks and crannies for shrimping.
Hoping to find a nice driftwood stump or two to make use of the tank height.