I use some road bike foam grips which seem to match the description Mark used for the Neon ones, They're thick, high density but still squidgy, and they come in 2ft long sections so you decide on the length.
Grip wise they're great and very comfy, sweat wise i find they absorb it then it slowly gets squeezed out of the end of them when riding, they've never slipped on me, but then again I've never ridden them in really hot weather.