Mich, If you are after companies for day trips like boat trips, jeep safaris etc there must be about a dozen along the main road in Hisaronu, Focus, Explora, Hamish McTurk & Carole & Tayfun to name a few. If you google their names im sure you will get some websites up on them. I have personally used Carole & Tayfun and Explora without any problems. Normally they are all priced about the same some may give a better deal if there are more of you or throw in a free trip if you book 2 trips with them.
Paul