Gunter
If I may offer a few words of wisdom in this regard. Successful commercial aerial photography is all about capturing the image in a better way than your competitors do. Timing is of the essence because whether you are shooting in a studio or outside, the light is the critical factor. Half an hour can make a lot of difference sometimes. Shooting with flat lighting may show some extra detail in the shadows but your customer will always want to see good color on a bright sunny day. You may need to shoot one elevation in the morning and another in the afternoon. So the sun position is the key factor. Partial cloud cover on part of the image is also a no no. Planning is therefore a very important part because you don't want to be shooting into the shadows. As Mobasaflash said, wide angle distortions don't cut the mustard. I shoot with a 50 mm lens in portrait and then stitch the panos. It is a technique that is widely used in architectural photography.
Another technique to create a low light highly manipulated effect, showing the lights on inside the house with that warm glow. This is done about an hour before dusk and then darkened slightly. This is an art form in itself and one that needs to be developed if you want award winning pictures. Most of this stuff can be done in Photoshop.
When you consider that most of the modern camera ISO tests start at 500 ASA and then go up to 25,000 ASA then you can see that low iso settings of say 100 are not going to give you any benefit, The opposite is true in fact. because what you need is the optimized performance from the lens which will be somewhere around F8.
A setting of 100 ASA or less is what we use for differential focussing effects in cinematography. Often used with a Neutral Density filter to cut down the available light. This creates a very narrow depth of field which is NOT what we want in AP.
Hope this info can be of benefit as you develop your business. There is no novelty factor these days, only the best can survive.