Answer:
Justification/ Recommendation Report
Explanation:
Since you have conducted the research and you have been given the power to determine a new provider, a recommendation or justification report is the best report to write in this situation. This is because you have found the new provider worthy by the standards of your research and it has plans that suit your company the most, you will therfore have to write a report recommending that new provider and also give reason as to why you are recommending that provider(justification).
Cheers.