How do I build a recruitment site for my client

Hi,
Thanks in advance for your reply and give time to read my query.

I am a wordpress developer with less experience. One of my client want to build a online staff recruitment website, main work flow for this website is as mentioned below.
1> Any visitor want to hire some staff for temparory. they choose any one plan. like 2 hour 250$, 4 hour 400$ from website.
2> After this they have to select candidate from list. whom they want to hire.
3> Pay online and confirm.

I search a lot on internet but could not find any thing which help me to solved out.

So, any one know how I solve this problem are most welcome and let me know how I create this.