It seems like everyone I know growing palms in Puna is at around 800 ft. elevation. I have an acre in Leilani Estates that is about 780 - 800 ft. elevation. Then when I drive to Floribunda or Bill Austin's, even though it feels like I've gone uphill, they are also around 800 ft. It's kind of an illusion because you drive gently downhill from Leilani Estates, then uphill into Hawaiian Acres. The same is true driving toward Volcano, where another friend is growing palms outside Kurtisstown. It seems I've driven way uphill, but his land is at around 800 ft. elevation. If you are down low, closer to sea level, as in Kapoho where the Pauleen Sullivan garden is located, you will get much less rainfall, and we all know palms love lots of rain.
I made my choice based on a number of preferences: general neighborhood quality and feel, quality of roads (I prefer paved), lot size, rainfall, successful palm growth, access to services, and price.