I suggest throwing some red in there somewhere (the text?) to go with Wildcat colours.
I figure that Ivy pic is a duplicate layer style effect. If that's right adjust the levels (ctrl-L) on the top layer so you can see the left side of his face better.
Technical: feather the pic of Pac so his right shoulder smooths out. Make the text smaller than the rest of it and say just "Nas - Got Ur Self A Gun". Smooth out the outer side of Nas' head.
Artistic: Just try some different layer effects on Nas + Pac, try some with 2 layers, some with 3 layers etc.










