For each and every one of my tanks, I added fish after 1 day, and they lived well. I think it is a load of huey, not to mention a massive waste of time and space, to let a tank cycle and mature for more than 2 months, even for Discus cichlids. I had a small puffer and I placed it in a five gallon tank the first day it was set up, using cycle and aquaplus. It lived for months before he kicked the bucket, and he was very happy and healthy thoughout this time.
Please, do yourself a favour and use biomax or bio spheres, with the mentioned chemicals, and place your happy new puffer into its new tank within 2 weeks. "Cloning" the tank is an excellent suggestion, but watch out for ammonia spikes. Most freshwater fish can be used as cyclers in a new tank anyways, so dont waste your time waiting unneccesarily for a tank to mature.
Good luck with the puffers!
P.S., what species of puffers are they?