The 164 is really short.  Being a rockered ski, the CRJ is going to feel like an even shorter ski.  Realistically, it will ski like a 158ish traditional camber ski.
The typical rule of thumb is to size up.  180 & 188 are the top selling sizes for that reason.  Remember, the CRJ is a very
 soft, fun, playful ski and they are very easy to ski and throw around.  Based on your height and what you want to do, I would recommend the 180 or 172 (at the shortest).
Nonetheless, you can't go wrong with 4FRNT.  We were just at 4FRNT party last night here in SLC...great crew!