As stated above, a football field is about 100 meters by 50 meters. That is a very small space for an airplane. You will need a slow flyer for learning. There were no planes at the links you provided so I don't know what you were looking at but if you have to have an RTF, look at the Slo-V from ParkZone.

As an alternative, on a really low end there is the AeroAce from Air Hogs. This is getting a lot of positive review from members of all the forums. It sells for about $30 at US toy stores. Not a great plane, but for $30 it seems to have enough fun factor to meet people's expectations. A football field in calm air would be fine for this plane.