I see "Back cover HD+ panel WiGig" has to be selected with a WiGig card when configuing the M4800. Does this mean if I don't order it now a WiGig card can't be added in the future without getting a new back cover?
The M4800 back panel will contain the systems wireless antenna. A WiGig card would require an additional antenna not included in the non-WiGig back panels. If intending to add a WiGig card to your system in the future I would recommend making sure those antenna are included with sales in your purchase, making installation easier down the line.