Apologies, I have just noticed your reply.
Unless I am mistaken (quite probably), but I thought Perch only ships with Redactor and Redactor 2. Did you purchase and install your own licence of Redactor 3.
As it turns out, I managed to get it working in redactor. I then tried to get the limiter plugin working, but ended up being pulled onto a different job, so I haven't looked at this in a few days