You can hire dedicated resources/team for a specific period of time (Contractual) to work on your project and you can make the payment monthly basis.
The hired resources/team work exclusively for you and report to you throughout the duration of the project, which means that they are not assigned to any other project or task.
If you choose this model, it provides you with the flexibility to hire resources as and when required, and you can scale up or down as per your project requirements.
This model also allows you to have full control over the project and the resources, and you can monitor the progress of the project closely.