Jennifer Kries has a pilates workout made just for you. Pilates With Toys.
Stott has several with a resistance band, circle, and small weighted balls. Total Body Toning with the balls is a favorite.
Mari Winsor said that if you sink your belly and flatten the area between your ribs it will help to hold you up. I don't know if that will help your neck or not. If you lift your head and lower it when it gets uncomfortable, you'll get stronger. Holding a tennis ball or an orange under your chin might help.