I also did not use Grapewood as its properties are not mold/mildew resistant and will deteriorate over time, so I used Ghostwood instead - Manzanita is also a good choice, but the branches are thinner.
I will tell you that I ordered 4 18" branches through them, and 2 that came in were barely 14", which messed up my build plans a bit. Fortunately they did refund me the 2 branches though and let me keep them.
Is also another good option. It seems odd to get them from craft stores, but I found out people use them for center pieces at weddings. This lets you buy them at a cheaper rate where with a pet store/supply they gouge you for 2-3x the cost.