I started doing this in the old shop. The one here is rigged with a temp plug (yellow cord) since it'll be moved and re-done when the new shop is in operation. In the old shop, I used a bottomless Handy box over an existing outlet as the tie-in for the assembly. This way, with some fittings and a bit of conduit, I can whip up something that fits and if I change things around, it's easy to take apart and rework to a new layout. The new shop will have several runs like this, starting with a backless 4" box over a flush mounted 4" box. the backless box will mount a GFCI and adjacent plug, then have conduit runs extending in both directions as needed with outlets fed off the load side of the GFCI.
>I am also scouring craigslist for industrial power strips such as used in IT data centers.
Our data center uses some power strips - most "industrial" looking ones just have a better color strip wrap than a Harbor Freight item. All Made In China, so don't spend too much. The 19" relay rack vertical specific power strips are nice and extremely pricey. the horizontal ones are nice, but no wider than something you could get at Office Depot - expcept they cost 4x as much. In a Data Center, you just need decent plugs - the money is in the power conditioning equipment that sits well before the system power connections. Very few plugs ever get removed after insertion unless the equipment is coming out of service, so there is little strain or abuse on the sockets. In fact - 90% of our data center plug runs look just like my picture - metal boxes and conduit screwed to a 3/4" plywood wall covering. They just terminate off a 20kVa UPS with three output legs.