I personally tend to gravitate toward the 124gr as 147 I think to heavy for the 9mm cartridge to try to push,... well. 147 is I believe considered a sub-sonic round, which explains its over penetration and non-expansion. Take a look at this though, I found it interesting.
http://frag.110mb.com/
Even though his experiment went well the 124gr is tried and true and the 147gr could be questionable. YMMV. I know I want what has the best possible chance to expand with good penetration rather than the chance of not expanding and over penetration. Just my opinion for what its worth.