C5z supercharged vs C6z

just want to get some opinions from others, i have a c5z with 28k miles, have all the parts to supercharge it and with install will be around 21k thats parts and labor , not including a new clutch or torque tube rebuilt, i have an offer for
my c5z and 19k cash to upgrade to a c6z with 28k miles , what would be your choice and why ? and the c6z heads have been done