I don't have much knowledge on that industry , but as far I know from seeing other people & talking to them, consultancy are run by crapist people . Most people choose not to run that business because you have to fake things and lie from morning you wake up till you sleep in night. Saying that they are leech to suck you up and make as much as they can from you. To do that they have to hold you as long as they can . When you take this common sense & mix with some data in Internet about which companies are filing immigration application, you should be able to come with list of few of them that might work for you.

I heard that there is one Nepali leech in Dallas Tx, if you like to get sucked by Nepali :). Further I will let others, who have been sucked to shed more light on it.