So.. I know this is a bit late but there is a BT keyboard that might be what you want:
http://amzn.to/2vc4NUoI've been using them since 2010. For me, I like the layout, lack of numberpad, and that's it's an ergo style with the curvature to it. Downsides are that they require alkaline batteries as if you use rechargeable it doesn't seem to behave properly as the voltage begins to drop and that they do not seem to last very long, like 12-18 months before they have to be replaced as the keys will just stop responding. Also, what's kind of annoying is that the Fn keys are on the option and not on the F1-F12 it seems and I can't seem to swap that role, wish I could though.
Also, the price. It seems to be at $50 now but if you hunt around or wait you can find them for $20-$30 or so. When that happens I buy two of them.
I am actively looking for a replacement. I do need dedicated arrow and would like function keys as my recent endeavor with a 60% did work as well as I had hoped.