Stagers come with different packages & possibilities. My wife is an Accredited Staging Professional and provides her services to our listing clients as part of our package. Other Stager's are independent business persons and do consultations, set fees or hourly rates depending on what is needed.
Renting furniture is a separate expense that stagers can arrange for, or provide themselves depending on what is needed.
My suggestion is find an outstanding agent and discuss your interest in professional staging with them. They may also have Professional Accreditation or a recommendation for someone they have used successfully.