Not perfect, but I do like flax bread (www.livefabuLESS.com/minutemuffin), it can be made sweet or savory, but I don't make it often as flax seeds aren't ideal.

The only other gluten free breads that I've enjoyed include dairy-- if that's not an issue for you, I'd highly recommend Brazilian Cheese bread, there are a number of recipes online but I buy mine fresh from a local Brazilian supermarket, or frozen in their freezer section (and then heat and serve). It's the first GF, non-grain (it's made with tapioca flour) that actually tastes like bread (actually, it tastes like pizza dough-- it's insanely good!)

The other option is this one: www.livefabuLESS.com/quickbread-- it's just eggs and cream cheese (again, I know, dairy)-- but if you do dairy, it's a nice option to have. It works great as a hamburger bun, too.

Not a direct answer to your question in the least I realize, but that's all I've got. Hope it helps :)

I disagree with your entire premise of so called "paleo 2.0".

... However, having said that, you can make rice flour rise. Buckwheat flour is good for pan breads, but you need to cut it with a flour with a glutinous or gluten-like protein (which rice has in a small amount).

This likely won't work for celiacs, but for those with a light to moderate gluten sensitivity, plain ol' wheaty real sourdough is usually tolerated. If you let it sour long enough, most of the gluten gets gobbled up in fermentation...and it rises beautifully.

My wife just got into this a few weeks ago when she bought her first starter kit. Since then she's made pancakes and waffles from it, but the best thing she's made, by far, is the sourdough bread. I'd put it up against any sourdough I've ever had!

Here's the recipe she's followed: http://www.cheeseslave.com/no-knead-sourdough-bread/

Free the Animal "Fat Bread"

I think this would count. I haven't tried it yet but if you're okay with nuts you should be okay with this.

5 eggs (medium to large size)
1 cup raw whole macadamia nuts (made into butter per the instructions)
1 cup coconut butter (nuke 20 seconds to get a smooth butter)
1/2 teaspoon sea salt
2 tablespoons lemon juice
1 rounded teaspoon baking soda

edit: I didn't catch the "sourdough" requirement initially (unless that was added later?). Sorry, this might not fit the bill then.