Rental car needed in Nairobi

We need a rental car starting from July 30, 2014 noon/afternoon until September 11, 2014 evening. We had someone to rent from but seems like he can not deliver.

Depending on the rate you offer either for the full time period as stated or if your rates are too high from July 30, 2014 – August 26, 2014 and from September 3, 2014 until September 11, 2014 as we will be in Mombasa from 27 August on and would not drive it for a week.

We are looking for something affordable, a Premio, Allion or similar. Newer cars only.