We only have 1 blubrry powerpress plugin.
As for formats you can use, any of these will work with the plugin: mp3, m4a, ogg, wma, ra, mp4a, m4v, mp4v, mpg, asf, avi, wmv, flv, swf, mov, divx, 3gp, midi, wav, aa, pdf, torrent, m4b, m4r.
I believe h264 is at lease one of these formats.
Give it a try.
www.blubrry.com/powerpress