Where do you source your grains for baking?

I'm a new sourdough baking aficionado (Thank you Kate Downham for your trouble shooting help!), and enjoy baking sourdough bread.
We buy our baking flour at the Local Products section at our supermarket, it comes from a local-ish mill.
BUT. I'd love to buy whole grain and grind it myself with a coffee/spice grinder for baking.

The questions that come to mind are:
- Where to source the grains? Online is a quick answer, but I'd prefer to buy local. How do you guys find your grains?
- Am I delulu with the thought of grinding the grains with a small electrical coffee/spice grinder? I did one test batch and it looks great, but for weekly bread baking the batches would be bigger... What are your experiences?
- What are your favourite liquids to bake sourdough bread with? I usually use water, sometimes whey, but have you used other liquids to bake bread with? What were the results?

Thanks in advance!

I use corn and oat flour.
The corn I grow my self. I 'grind' it in a standard kitchen blender.
The oat flour I also make in the blender. The source is commercial oat meal.
We mostly fry, not bake.

I get most of my grains from Bluebird Grain Farms in Winthrop, WA.  I also get some from 1000 Springs Mill in Buhl, ID and some from Azure Standard.

regarding sourdough, My son has made sourdough for years, has read the Tartine books, and he is convinced that to get consistent results the kitchen has to always be maintained at the same temperature.  He also collects wild yeast when he moves to a new location, so he's pretty serious about it.

We also went to a class together from Richard Bourdon in Housatonic, Massachusetts, in search of the perfect sourdough!

Maybe I am just not patient enough, but I get very inconsistent results.  It is a lot more work than just using commercial yeast to have failure.  I also haven't figured out how to manage the amount of waste of starter except to put it in the compost.

I would love to win a copy of "Sourdough Without Fail."  I really prefer the flavor, I think it is healthier and I want to try again.
 

There is no one source that we rely upon solely. We have a big farmer neighbor who understands our approach to life and he frequently gifts us wheat that he is sure is pesticide free. While it may not be certified organic …I suspect it may be better.  I am pretty sure he has set aside an acre or so to provide grain to several of his neighbors.  Anyway, our share is somewhere between 60 to 120 pounds.  It being a gift, I don’t question him too heavily….i accept his gift as well intentioned.