Meaningful and authentic

One of the ways that Mr. Spaniel and I hope to personalize our ceremony is by finding readings from different faith and cultural traditions that are meaningful to us now, or that speak to our particular backgrounds. This isn't necessarily as simple and straightforward as it sounds, though. In our first year together, we attended three weddings, and at two of them we heard the "Apache Wedding Blessing." It may be familiar to you:

(source)

Now you will feel no rain,
For each of you will be shelter to the other.
Now you will feel no cold,
For each of you will be warmth to the other.
Now there is no more loneliness,
For each of you will be companion to the other.
Now you are two bodies,
But there is one life before you.
Go now to your dwelling place,
To enter into the days of your togetherness.
And may your days be good and long upon the earth.

(You can even buy calligraphic prints of it here or here!)

Sounds sweet and sentimental, right? Old and traditional? The perfect reading for a couple of semi-hippie types like Mr. Spaniel and I? Yeah, except that it's a giant fraud. Mr. Spaniel thought it sounded just a little too perfect and did a quick Google search on it, and discovered that it actually has no connection to any Native American tradition at all, but was instead written for the 1950s Western Broken Arrow by Brooklyn-born Albert Maltz. Naturally, we've decided to continue the search to find something both meaningful and authentic to incorporate into our ceremony.

Am I being too sentimental? Does it matter if this is a real Native American tradition or not?