Checken wire works fine. The disadvantage is that you have a higher wire to cell ratio and a higher percentage of bees will be damaged in the cell or fail to emerge.
The split bar idea works really well. You can squash the top of the comb between them really tightly and wire it together at the ends. The disadvantage is the split bars warp more readily, and you also have the problem of a lack of uniformity in thicknesses.
Usually people cull these combs as soon as possible anyway, no matter which form of framing you use. I just use hemp bailing twine. I spread the strands of twine at the bottom, and so long as its brood or pollen it holds up just fine. It has the advantage of being adjustable, so that if I didn't tie it tightly enough, I can just spread the ties apart at the top to draw the bottom back up. The bees then attach the comb on their own within a day or two and I can remove it. If the combs are really good and attached well, I don't have to cull it at all if I don't want to.
Scot Mc Pherson<br />McPherson Family Honey Farms<br />Davenport, IA<br />BeeWiki: <a href=\"http://beewiki.linuxfromscratch.org\" target=\"_blank\">http://beewiki.linuxfromscratch.org</a> <br /><br />Pics:<br /> <a href=\"http://linuxfromscratch.org/~scot/pics/bees/\" target=\"_blank\">http://linuxfromscratch.org/~scot/pics/bees/</a>