Please advice if h1 applied without COS make sense

[Garima arora]

I entered US in feb 2012 on h4 visa. I am planning to look for job this year and wanted to get h1 visa done in 2013 cap. Found some consultants also, who agreed to file my visa. But the problem is that I have to travel to India from April till may end . My consultant is saying that they can file for h1 once cap opens and can apply for COS later. I wanted to know will this effect h1 approval? If I apply for visa change is it fine to travel outside US ? If I apply for h1 will I be able to return back to USA without visa stamping done from India?
Replies will be highly appreciated.

Thanks
Garima