I agree with the don't get a 4 channel radio bit. There are a lot of planes that use only 4 channels but a lot will use 6 or 7 channels, like when you get to planes that take retracts, flaps, bomb drops, etc.

Another bonus to getting a radio as the same brand as others at the local flying field is that you can use a buddy cord without buying extra equipment.

Don't forget that you still need to buy covering and the associated tools. For Monokote, Ultrakote or any of the other iron on coverings you can get by with getting just the covering iron, without the heat gun, but I would suggest getting the hot sock and the hot glove too.