dunk packages help

Alright my first question is there anyway for me to get the sprite dunk packages the servers are shut down for xbox 360 and the codes won't work as a result of that.

My second question is what are the best dunk packages for posterizing on people I have the signature skill and I get more dunks but I feel I still layup when I should be dunking also my player is 9 feet tall and he misses layups like crazy which is why I want to dunk more.

Also sometimes my player is about to dunk then stops and does nothing

Any help would be great