Flatter or more camber, thinner or thicker, the best choice will change with a small difference in ice surface and wind temperaure. Longer is a little better. Flatter is faster. Soft clear white ice- soft steel also works. Stainless is usually better.
Soft stainless is often good.
304 or 314 or 301 works great. Longer is good, unless the ice is very soft. When the blades sink in and make chips, go fatter. Fat blades or angles. Short blades resist less when turning and may be better.