after years of sub-contracting i am being offered a lot of domestic work and need to join the nic or one of the others so i can certify my own work.i could do with some advice on which one is best for me,prcedure cost and the length of time from application to actually being able to certify.i haven't got 2391 yet but want to do it in the next 12 months,any help advice would be appreciated