I have found it difficult to find information about these kind of alternative flours in relation to South Beach Diet. I think in general, if the whole product is allowed, then the flour would be as well, but in moderation as grinding a whole grain finely definitely increases its digestability. So you would have to be on the lookout for cravings these things might cause.
From previous discussions, I know that almond and peanut flour are OK. Also flaxseed meal, chickpea flour. BUT for Phase 1, the flaxseed and nut flours would be limited by the nut & seed restrictions outlined in the food list. So chickpea flour, or some other bean-based flour, might be the only types allowed in any kind of reasonable volume in Phase 1. I'm not sure about that, though. I haven't really found any bread-like substitute for Phase 1.
Kalyn's Kitchen lists brown rice baked goods for Phase 2, so it's probably considered OK. Here is a list of her gluten-free recipes
. Also quinoa flour and oat flour should be OK.
I like Elana's Pantry for gluten-free baking; most of her stuff appears to be SBD-compatible. She usually uses agave as a sweetener and often uses almond flour. Here are Elana's Pantry bread recipes
From a search of "gluten-free South Beach" I found this low-carb baking list
, which would give you an idea of where to start, though you will have to decide on a case-by-case basis if these fit with the idea of SBD.
I think it would be hard to eat these things on a regular basis and lose weight - all of these grain and nut flours are pretty calorie-dense. And if they cause cravings and/or binges, then look out!!