Hoi,
We have supported input methods and web fonts for the Bhojpuri language for quite some time at translatewiki.net. In essence it needs the same support as Hindi. We are happy with the results and intent to make them available on the bh.wikipedia.org. Have a look at translatewiki and let us know if there are any issues [1]

When you read about the Bhojpuri language at Ethnologue [2], it is indicated that the language has also been written in the Kaithi script [3]. When there is a freely licensed font for the Kaithi script, we are quite happy to provide this as well as an option. If you know of such a font please let us know.
Thanks,
      Gerard

[1] http://translatewiki.net/wiki/Portal:Bho?uselang=bho 
[2] http://www.ethnologue.com/show_language.asp?code=bho
[3] http://en.wikipedia.org/wiki/Kaithi