I use all mediums, natural comb and no wire and I extract them fine. But if you want to wire them, I'd do one of two things. Either put two wires horizontally (as evenly spaced as the predrilled holes allow) or I'd put them in an "X". The advantage to the "X" is that the bees will follow the wire down as they go better. Either way, with foundationless beekeeping it's important to have the hive level so the frames are plumb. The combs will be plumb even if the frames aren't which can lead to the wires being outside of the midrib or the combs actually running from the top bar of one frame to the bottom bar of the frame next to it.
As far as HOW do you wire, I put a small nail partly in and wrap the wire around that to start, then go all the way around and wrap back in the same nail and drive it in. Stainless wire from Glory bee is the best I've found. I have no had ANY luck with ANY other kind. Fatbeeman on Beesource uses fishing line.
Sorry I don't have pictures of the wire without foundation, but...
Here's two horizontal wires (but with foundation):
http://www.bushfarms.com/images/Foundation49.jpgHere's an "X" (also with foundation):
http://www.bushfarms.com/images/FrameWithXWire.jpgHere's a nice foundationless ready to extract with no wire:
http://www.bushfarms.com/images/FoundationlessDrawn.JPGhttp://www.bushfarms.com/beesfoundationless.htmThere is no purpose for support pins with foundationless. The pins are only to hold the foundation straight until it is drawn.