A couple ideas:
You can never depend on any round to expand no matter what the ballistic gel tests show.
Penetration is important. Fragmenting bullets are out.
If you shoot one weight better than a different weight, use the round you shoot best.
You will get 10,000 different answers on the 'best' round. In reality all these things do is poke holes. Myself, I use a round that my local law enforcement uses. If I ever need to defend myself I think it will be better to be able to say I use the same stuff the cops use instead of trying to explain why I am packing 'Zombie Killers' or something.
You can search and find hours and hours of reading on this, I have and there's a lot out there. Then when I read what the trial experts said, I just went with their recommendation. Right or wrong I don't know, but you have to make a decision and then live with it.