Make some WordPress plugin modifications

I'm using the 'WP Car Manager' plugin and Ninja Forms on an existing website. Firstly, I'd like to add a new data field to WP Car Manager, allowing me to pick from a dropdown list in the admin panel. The field will be 'vehicle type'. The choosable answers will be car and van. All current vehicles in the database will need to be set to 'car'. Then, in Ninja Forms, I will need two quotation forms (this is for vehicle leasing). One for car leasing and one for van leasing. The car leasing form will pull the data from WP Car Manager and allow the user to select a vehicle manufacturer and then model in two dropdown menus, but only displaying cars and not vans. The van leasing form will be the same, but obviously for vans and no cars. There will be other fields on each form, e.g. name, address, phone, email etc. When the user submits the form, all of the data is sent to an email address as well as stored in the website's database. When the form is submitted, the user will be given the estimated price for leasing the vehicle (data that is stored in the WP Car Manager plugin). As you can see, it's a basic integration of two existing plugins that will probably just mean making some template edits and SQL changes. It's a short, simple job for someone who knows what they are doing. Budget is low as it shouldn't take very long, but there will be more work afterwards for the right freelancer. Alex