Great. One thing I should have mentioned and may want to call and make sure can accomodate. There are 2 almost mandatory add-ons that neither Dell nor anyone else would include or even have available for a build. You want to make sure you can add them aftermarket.
1) a WD Purple (or Seagate Surveillance) hard drive for the video data separate from your drive with the OS/programs. Make sure there is a second SATA port on the motherboard available for hooking up the drive and that the case will physically support 2 hard drives. (micro case - eliminate; small form factor - varies, either OK as designed or be creative, move one drive to unused DVD area; medium/tower - OK)
2) a second NIC. Cards are cheap and typically low profile so will fit in most cases (excluding very compact micro - which also wouldn't have room for a 2nd drive) so need to make sure there is an available PCI Express slot for the card.
The only reason I mention this is that 1) marketing material isn't that specific, and 2) cost cutting has shifted away from 'off the shelf' motherboards to custom spec'd motherboards that support the intended build and eliminate other features to save cost which adversely limits expansion. Historically, Dell has used Asus boards but had a shock when purchased an HP from Costco several years ago (and returned it). A no-name board with zero expansion capability despite despite being in a mid-size case. While I haven't looked at Dells, reviewing their downloadable manuals showing board schematics and case accommodation for 2nd hard drives, it could be an issue...so ask the Dell rep.