May I suggest building up your kit in the comfort of your own location, with staff, tools and coffee on hand, to only install it at the datacenter once it's all set up, complete and known to be in good working order - at least the hardware, OS and basic stack you are going to be running. I get that this isn't always an option (e.g. when replacing burnt out kit on the fly) but for regular installations I think it's a lot more practical - it prevents this kind of potentially painful scenario where you're stuck at the DC build bench because some part or cable is wrong or missing.
Also, I'd personally prefer to set up a separate (from the rest of the rack) maintenance connection on the rack, or bring my own Internet connection in the form of a mobile Wifi hotspot (a phone with a data plan will do just fine for downloading some docs or patches) . Local Wifi availablility is not something I would want to have to rely on when troubleshooting. Having my own uplink also allows me to check things like loopbacks and what a system looks like to the outside world - and that I can make sure that whatever the server is supposed to be doing, actually amounts to anything at HQ without having to call in and ask someone to check if system X is now visible on the network, or having to wait and see what happens - fingers crossed - when users connect.