bellsux - try FLIR Systems (US company) - they provided the IR camera we are using in UK mil SAR at the moment and it is very good. It uses the latest QWIP (Quantum Well Infrared Photodetector) technology and has a very small Stirling pump to cool the detector quickly. It was procured to give the capability to find a person in the water and works very well.
You might need to have an IR detector working in a different band of wavelengths depending on the climate you will operate in but the company will advise you on that. Our removable turret also houses a daytime TV camera but I suspect our installation would be too big for a 109.