Well, this is an area where I need the help of the experts.
I've added a long extension to make a breakfast bar area--effectively a continuation of the kitchen counter. I have added a old work box at the end for a new GFI 20a double outlet (run #3 for the kitchen), but I need to add an outlet midpoint between the wall and the rest of the kitchen counter to meet the 4' rule (Thanks Will for the walk through!).
I physically could not add a new box above the counter when the wall was open because of solid framing behind--a combination of low window and doubled up 2x in the wall.
I found what seems to be the solution with this pop-up box from LEW--it is their PUP-CT-BK (black) or PUP-CT-SS for stainless. This is UL-approved to meet NEMA requirements.
http://www.lewelectric.com/cfm/comm_pufp.cfm (first two in list)
I also see mention on another thread for this box that some inspectors will not approve this as the first box in a GFI run.
Assume that I install the pop-up on the counter-top surface:
1.Can I wire from the existing counter end box attached to the underside of the counter?
Plan A would be to bring the BX out of the side or bottom of the new double box.
Run it behind end cabinet, physically attach to underside of counter top tight to the wall.
Would I use BX or? Can I use NM instead, or would this be considered exposed?
Just to confuse matters, for some reason, the install instructions I have read from APLUSSupply speak of using conduit:
http://www.aplussupply.com/lew-floor-boxes/pufp.htm and see the link labeled "Instructions")
Then the new wall outlet becomes first in string--GFCI on first outlet and surface mounted box is last in chain, so I have avoided the problem of it being first in string.
Plan B would be to snake a new circuit up through the wall cavity, exiting a little to the left of where the box would sit. Then it is first in string...
If I adopt Plan B, would I need to use BX or could I use NM?
(reason for asking is that I have the most god-awful footing/wall cavity situation to get wires up from the crawl, that pulling a new BX may cause me to lose it completely and burn the place down.

)
Cheers,
Dean