I mean the height of the person's image should be at least 1000 good pixels. Good pixels as in you use a good prime to shoot, and you also gotta factor in loss due to Bayer CCD interpolation. Usually say a pic of 2000 pixels, you resize to 1500 pixels will do the trick. Subsequently to get 1000 good pixels, you need to have at least 1500 pixels originally, give and take for illustration. For Foveon sensors, you don't need to resize. The printer will do the rest of the work. This is for a low-quality life-sized standee, no problem if this is for printing out a celebrity and you let fans stand beside to take picture, for eg.
If the image is to be used commercially like say for a standee to be in SingTel/M1 shops with price plans advertisements, this wouldn't do of coz. You did mention minimum requirements right?