This is not a good idea to generate any image for a particular printer. If your users or your organization change the printer, should they ask you to write different code? This is not supportable. It's the best to generate image and print it as image in required resolution.
As to the barcode generation libraries, you should specify exact type of barcode according to some particular standard. Barcodes are different, so not all libraries may support all types. I don't know why did you fail to find some. Try:
http://bit.ly/15FGnNY[
^],
http://www.codeproject.com/search.aspx?q=barcode+%28%22.NET%22+OR+%22C%23%22+OR+%22VB.NET%22%29&doctypeid=1[
^].
For example, see these CodeProject articles:
Barcode .NET Control[
^],
Creating EAN-13 Barcodes with C#[
^].
Need some different barcode type? I told you, you should have specified it. But I'm sure you will be able to find appropriate library. And most (or all) barcodes are simple and well specified, so you can simply find the specifications (use Wikipedia to start with) and develop an image-generating library by yourself.
—SA