You must do a safari. We had one prebooked before we went (2 nights, 3 days) we saw Tsavo East, Tsavo West and Amboseli. Cannot recommend enough, we saw all of the big 5 plus so much more wildlife (you can get really close too). We went in September 2004 and saw baby elephants jackels, warthogs, lion cubs.... the list goes on.
Infact we had such an amazing time on safari we booked to go on another while we were there. We went to the Masai Mara, saw the wildebeest migration, probably the most amazing thing I have ever seen. Just like the TV programmes, hordes of them, crossing the Mara river - WOW!!
You don't camp out under the stars (!), we stayed in perfectly good and clean hotels with breakfast and evening meal included. One of them had an idea of hanging a sign on your door handle and if a leopard came during the night they knocked to wake you up!! We saw one! I understand your concern about staying 'out there', but honestly the hotels are fine. One of the ones we stayed in had a spa, swimming pool and viewing pier overlooking a watering hole, the rooms were built so that you could see the watering hole from the veranda/balcony - stunning.
Please, don't go all of that way and miss out what Kenya is truely known for. Once you've done it, you'll be glad you did!!
Bear in mind that the 'parks' are a long way from the coast, so a really long drive is needed, it took us most of the morning with a v v early start to get to the first reserve (we had to fly on the Masai Mara trip).
Have an amzing time, it is a fab place, I think I left a piece of my heart there!! Be prepared for a real culture shock if you've not been anwhere like this before.
L x