Side Note #1 - Featherlight Boning

In case any of you out there are thinking about using the plastic Featherlight Boning which can be found at almost any sewing shop, including Joann's Fabrics, for any corset-type project my advice is this: don't. The only time that this stuff works for corsets or bodices is if you are without any curves whatsoever. Since most women today, myself included, don't fall into this category we have to look at other options. Just for laughs I will post a photo of my bodice with featherlight boning after one day of wear here: 

You can see that the plastic has bent, clearly warping the bodice after only a short day of wear. Not to mention that it causes the front points of the bodice to roll up in a most unbecoming manner!

One popular option is Spiral Steel Boning. This is the more flexible of the two with its being flexible in all directions. However it may not be appropriate for all boning uses. It does work remarkably well for those situations when boning has to follow along a curve. It's also the more comfortable of the two for long periods of wear. 

The other option is White Steel or Sprung Steel Boning. This is more rigid than the previous option and doesn't give so easily on all axis. It will not bend to fit the curved seams like the first and unless you are used to it, can be uncomfortable for long periods of wear. 

I have worn garments made with both and I find that the more rigid of the two I found more comfortable. That is partially a personal preference as well. My best recommendation would be to get a set of each and find a way to try on your bodice with them. Better yet find a friend who is similar in size and body type and see if they'll let you try theirs on so you can get an idea of what they feel like!!