HELP ME CHOOSE A DELL NOTEBOOK, PLEASE

Depends. 15Hours every day, also weekends exceeds the proposed usage of HDD. Other components I don't think matter so much. It is the harddisk which limits your time There was a whitepaper for some specs of an HitachiIBM hdd saying that the mean lifetime of nearly 50years is computed by multiplying 8hours per day five times a week. If you use this hdd beyond the reliability lowers extremely- and not linear but exponentially. Only SCSI disks are made for this- that's why they are most likely to be found in servers. You have two choices- depending upon your needs. One really powerful PC and a laptop. Or maybe a laptop and an image on a second harddisk of all documents and the operating system. But if you e.g. need to compute a 3Ds max animation you will have to wait up to a week or more until the scene is completely rendered- which in itself gives you the need for a second PC. What exactly is your need?