Hawaiian Bread, aka Portuguese Bread, makes excellent altar bread.
If you don't over bake it the crust is nice and soft and doesn't crumble. You can mix this in a bread machine on the dough cycle, use a high powered mixer, a food processor or mix by hand. Be aware that if the congregation is used to the flat wafers they tend to shy away from large pieces of bread. Here is my recipe:

Hawaiian Altar bread
Printer version of this recipe

2 large eggs (that is 1/2 cup of egg that has been slightly beaten)
3/4 cup buttermilk (may substitute sour cream or yogurt)
1/4 cup honey or sugar
1/4 cup olive oil
1 teaspoon vanilla
1 teaspoon lemon extract (optional)
3 tablespoons lemon zest (leave this out for altar bread)
1 teaspoon salt
1/2 teaspoon baking soda (this is used to cancel the acid flavor of the buttermilk. I don't use it.)
3 cups strong bread flour
2 1/4 teaspoons yeast. Don't skimp on the yeast. This recipe is using a lot of sweetener. Without the extra yeast it could become exhausted too soon.

Add the ingredients to a bread machine in the order listed.
Set the machine to the dough cycle.

After the ingredients have mixed for about five minutes check the dough. It should be smooth and when touched be slightly tacky without coming off onto your fingers. The dough should be pulling away from the edges of the pan. If dough is too dry add water (1 tablespoon at time) until the dough is smooth and slightly tacky. If the dough is too wet add flour one tablespoon at a time until the dough ball is as described above. If you need more time to adjust the dough, reset the machine and start the mix/knead cycle over.

At the end of the dough cycle take out the dough, and place on a lightly floured surface, flour you hands and knead the dough slightly, form into loaves.

Divide the dough into several pieces. Use mini bread pans for loaves. Roll the bread into a log shape for loaves or into a ball for free style flat loaves. Press the balls flat and place on a baking sheet or place the logs into the pans.

Cover and let rise in a cool place until doubled. You can press a cross design into the loaves or use one of the stamps sold at Eastern Orthodox religious supply houses to to press a design into the loaves.

Preheat the oven to 350 degrees F. Bake from 10 to 30 minutes depending on the size loaves.

The bread should be 190 degrees when measured with an instant read thermometer. When done let the bread cool on wire racks. When cool cover bread with plastic wrap. This will soften the crust and help keep the bread cool. You may freeze the bread.

Some folks like to pre cut the loaf a little to assist the priest at the Fraction.

I strongly urge that you try making this bread several times before attempting to bake it for church use. You may need to adjust the sizes of the loaves or adjust the recipe to suit your ingredients, altitude, etc.

There is a flour company called Wheat Montana that makes a wonderful white flour and the best whole wheat flour I've ever used called Prairie Gold. You don't need to mix white flour with Prairie Gold if you want a whole wheat bread. Wheat Montana flour is only available in the western states, alas. But you can use a mix of white and whole wheat flour if you desire. My family and friends love this bread...so do I.