Need help matching heating element to still and opinions

[scooter]

hi i just finished building an offset head design and i have a few questions...

ok i am using a 7 gallon beer keg for the boiler, i didnt have an affordable method of obtaining 2" copper so i went with 1"...

my colum is 24 inches from the keg to the tee fitting with an 14" jacket style condenser... both the colum and condenser are packed with copper scrubbers and everything is ready to go... all but the heating element...

what would be a safe wattage to go with... the lowest wattage i have found locally is 1500W water heater screw in type...

any suggestions?

thanks in advance