Shoes for walk aerobics

I am an avid walk aerobics exerciser - Leslie Sansone's Walk at Home DVDs, as well as Jessica Smith's YouTube videos. I've been wearing my running shoes (along with an orthotic for my high arches), and I find the outside of my feet ache after a workout. I am not getting enough lateral stability with the shoes I have now, so the side steps really do a number on my tootsies. Anyone have any suggestions for a great supportive aerobics shoe? BTW, I work out on carpet.