I was super excited to see that baking functionality has finally made it into Cycles. But I'm a bit confused about its usage. There are a lot of options in there. I'm able to get baking working just fine I think, but I'd like to back just a light map. There doesn't seem to be an option to combine bakes (except for one big combination of every thing). So I'm guessing I need to bake multiple maps and merge them in Photoshop. I'm just not sure exactly which ones I need. I'm guessing it would be Shadows, AO, Diffuse Indirect, and Diffuse Direct? Am I missing one? Is there some way to have Cycles bake those four together at once?
As a side question, just because I haven't tried it yet, if I make a second UV channel for my light maps (say one using Lightmap Pack in the UV tools) and set the image that I light map on to use that one while keeping the actual materials on the first one, will that give me the results I want? I don't want my materials to go wonky when I create the second UV set but I've never worked with multiple UV channels before. Certainly not in combination with baking in Cycles.