This is a ZooMed betta leaf hammock- If you get one make sure the wire in the leaf is not exposed in any way so your betta doesn't get hurt. I've had mine for a year and it's still fine.
The ZooMed floating Betta Log- I don't have one of these yet but I do plan on getting one. Lots of members here say their bettas love them.
Some people have also made leaf hammocks for their bettas out of a suction cup and some silk leaves, to get around the wire stem. I think you can find instructions here somewhere, or perhaps on youtube if you decide to go the DIY route.
As far as clay pots go, you can use any cave, just make sure whatever you use doesn't have holes small enough your betta could jam himself part of the way into and get stuck. Fill in holes in the clay pots with aquarium sealant or something. Make sure decorative caves don't have "window" cracks that are smaller then the largest part of your fish's body.
These things intrigue me but I can't find any locally. Cichlid Stones:
I may just cave and order some but I'd REALLY like to see them in person first, or at least have more input from people who have used which stone for their bettas before I shell out anywhere from $5 - $80 on a single stone, or a 15 pack.... I do like that they are made of ceramic though and they look realistic in pictures.