UAV Drone Power plant calculations

I need someone to research a variety of power plant options for some heavy lift drones. There are 4 lift masses to work with. 1. 100 kg 2. 500 kg 3. 2000 kg 4. 5000 kg The power to weight ratio will be approximately .3 (kw/kg). These would be piston type engines found on Cessna aircraft up to and including high performance engines like those found on the M1-Reaper and Preadator drones. The goal of the research is to identify at least 5 engines for each weight class that would provide the required kw/kg ratio. The research will need to include PDF files of specification pages and respective links to go along with the chart being produced. Examples of aircraft using the engines are also helpful. As is my custom, please tell me your favorite type of car. This helps me gauge whether or not the respondent has read the whole post before bidding. Thanks! Andy