AfriCan66, a very warm welcome to you
How wonderful to have 14 days.
I am going to focus on 2 important aspects of your trip... teenagers and being new to Kruger. I have made the mistake in the past in thinking that everyone had built up wilderness awareness. Teenagers often need a lot of adventure and stimulation.
Skukuza remains a camp that offers everything. Some people think it is too busy, but once ""the lights go out"' it is magic. It has wonderful walks, gardens and places to explore. It also has 2 good swimming pools to cool down in hot weather.
Lower Sabie This is a camp in a prime big five area. I think that the choice of roads offers some of the best big game possibilities. It is an excellent camp for night drives and/or walks. It also has different restaurant options.
Satara. In terms of predator country, you cannot get better. It is another big camp, but with teenagers, they might enjoy the activities. I also think that it offers good opportunities for game drives.
For a very unique experience I would suggest Tambotie. This is bush at its best. Its a tented camp that gives an excellent wilderness experience. I think that it would evoke the adventurous spirit in the boys.
Olifants, the camp with the best view. It really is worth staying a night there for the experience of beauty at its best. There is the possibility of bicycle trails, but I am not sure if there is an age limit.
I hesitate to recommend too long in the north for new visitors unless they are birding fans. If you do want to travel further north though, Punda Maria offers the best variety. Maybe think of zivvy&muffin's suggestion of Shimuwini as a stop on the way down. Sirheni is also a firm favorite.