Ice is far softer than steel, even annealed mild steel. It should not pose any problems for either. The only worry would be rocks or other inclusions frozen into the ice. I have an old drywall hammer I use everyday to chop ice in the winter.
However, ice chopping is a good test for handle ergonomics, hanging onto a knife cold, wet handle under hard imapcts with numb hands will test ergonomics in a most significant way (especially if you slip!)
As to your question, I like the RAT-7, there is a review on this forum somewhere that I wrote a couple years back, actually has some ice chopping in it.
Justin of Ranger knives is great to deal with though, and I have used the heck out of an RD9, it is my "garage" knife and is basically used a prybar/woodsplitter/destroyer of things that need to be destroyed to fit in the trash knife.