Richard,
Tough area of the business. Open your eyes very wide before jumping in !
If you do, please, please look at it as photography first, mast second. So many people (loads now packed up) have looked at it as mast first. There are people out there hawking awful elevated photos (no I absolutely will not point the finger). Happy to give advice if you want it. Unless you think I stink and want to seek it elsewhere !
Matthew