Be careful with powdered Splenda. It has dextrose and maltodextrins as fillers and respond like sugar in the body. They are high glycemic.

I know that Dr. Ann de Wees Allen (Glycemic Research Institute) is not a proponent of the Atkins diet, but she does have zero carb/low glycemic sweeteners on her website:
http://www.anndeweesallen.com
under "Dr. Allen's Products."

She also has zero carb sweetened coffee and tea. I think she also has an energy drink. I haven't tried it yet but I think I'll order some to try it.

The article she has on the coffee/caffeine
thermogenic connection was quite interesting.

I have ordered the Trutina Dulcem sweetener and it tastes like sugar. A little goes a long way. I think I'll order the Ki-Sweet also. Let you know how it tastes...

Steel's has maltitol in a 2lb. bag that is available on various low carb websites as well.

Hope this helps...

Misuzu