Ditto what flying ace said. The 55's will do you well, the 81's are a bit of overkill.
Don't waste your money on a second PZ rx and servos. They will cost you in the end.
As for a tx....Well here's what I tell any beginning pilot. Ask yourself if this is something you plan on continuing with. If it is, don't go with a 4 channel radio. When you get more experience under your belt, you'll want to go with more options on your planes, like landing gear or flaps. Can't do it with only 4 channels as you are using them for the control surfaces and the motor. Look at a 6 channel radio to start. Buy the best you can, as it will last you a long time.
I have somewhere around 20 birds, and I use 1 tx and I've had it for years.