Evo upgrades

hey there I have a 2003 evo my upgrades now consist of exaust manifold,turbo outlet,super suction intake kit,underdrive pulley,dual stage manual boost controller,apr stud heads, and turbo timer I want to get new ecu,cams, and gears next what would you go with? Oh and also how high do you think i can put my boost with out blowing sumtin?

my friend runs 22psi on his evo.