Hi new to this and theres so much to take in the nvr i was thinking of going for is the DS-7716NI-14/16P to run 10x 8mp cameras 3 running 24/7 the other 7 triggered via movement i had read that 2x hdd's are better than running just the one is this correct? Also would 2x 4tb hdd's be sufficient for this? Note i may add a few extra cameras at a later date too so want the capacity to do this though they maybe small covert cameras just thinking of future proofing. The only thing that i am still unsure of camera wise is colorvu or acusense. So to begin with i am thinking of purchasing one of each to enable me to evaluate them and decide on positioning. I have read that its posible to run these cameras without the nvr. What i would like to know is since i am new to this is it going to be easier for me to run the cameras with the nvr or on there own to work out the best position for me to place them in, do i need any additional equipment and how easy is it to do this. It feels like i am taking ages to make my choices here but i want to try and get this right from the begining.