The weight difference between the stock aluminum axles and the steel AD2 axles is insignificant. The added durability (I've sheered many aluminum front axles) is what you'll actually notice, not the weight. I've been running steel axles on my electric trucks for years.
I'm actually curious to hear what the weight difference is! Someone throw a pair on the scale for me? haha
But to answer your question...no, Losi doesn't make AD2-style axles in aluminum.