You can't do this there, you have to do this in your onLoop:
NPC bank = getNpcs().closest("Banker");
NPC clerk = getNpcs().closest("Grand Exchange Clerk");
You can use my utitlites script to do exactly what you asked
Account builder script with multi skills is not allowed on the store, but you can use script queueing to do exactly what you asked
Well I have the code so I know exactly what it does, I still believe my own facts over anything else.
Feel free to grab a simple vid or whatever to show me what you mean... because I have never seen or heard this before.
Enjoy!