I need to buy consultant roster system

I will be very thankful if someone can help me to buy consultant roster system for my wordpress website. I found this system developed by UNFPA useful, https://erecruit.partneragencies.org/psc/UNDPP1HRE/EMPLOYEE/HRMS/c/HRS_HRAM.HRS_CE.GBL?Page=HRS_CE_JOB_DTL&Action=A&JobOpeningId=2259&SiteId=1&PostingSeq=1

If I can buy similar or the one which is in above link that will be really great.