Yes
Technically you dont need a monitor with a CCTV system if you are going to view it remotely using client software, but how are you going to program the remote client settings in the first place? The OP is asking if he has to buy one or not, of course he does he cant program in his ip setting or put it into engineers mode even without one!
Mind you if he is asking the most basic question as does he need a RKP or not, I think my question would be does he need to start somewhere a little more basic, before he starts throwing piles of cash at it.