Experienced Mechanical Engineer – Concept for an Off-Road Utility Vehicle with Tanks

I am looking for an experienced mechanical engineer to develop 2–3 simple and affordable concepts for a small utility vehicle. The vehicle should: - be designed for a seated operator, - travel at speeds of up to 10 km/h over wet ground, sand and uneven terrain, - operate outdoors in rain, snow and freezing temperatures, - have large wheels and either single-axle drive or 4×4 drive, - operate in the field without access to mains electricity, - preferably not use a battery-powered traction system. The following equipment will be installed behind the seat: - a 100-litre insulated stainless-steel mixing tank, - a 200–250-litre plastic water tank, - a pump with a capacity of 40–60 litres per minute, - an agitator and other necessary equipment. The transported liquid will have a density of approximately 1.030 g/cm³. It will be heated to approximately 40°C at a stationary location. In the field, the requirement is only to maintain its temperature for as long as reasonably possible. I require: 1. A comparison of 2–3 drive options: mechanical, hydraulic or electric powered by a generator. 2. A recommendation for a suitable ready-made base platform. 3. Basic specifications for the main components. 4. Estimated costs. 5. A recommendation for the simplest and most affordable solution. 6. A preliminary layout of the components, taking the vehicle’s stability into account. The applicant must be a qualified mechanical engineer with practical experience in designing or selecting drive systems, vehicles or mobile machinery. At this stage, I only need a practical technical concept, without detailed CAD design or manufacturing documentation. I am looking for a simple and affordable solution.