As the first option is lowcost IPC-HFW2431T-ZS I would advice you to consider 2Mpx Starvis version IPC-HFW2231TP-ZS. Compared to 4Mpx friend I dont see extra value. Doing my own test I liked 2Mpx version better. 2Mpx version has got better colours at day, at night its got les noice and comparing...