H4 Visa through third party - Any thoughts/experience?

Hi,

I have limited vacation for my marriage. My employer will not process the H4 visa until I got my Marriage certificate. Blocking the interview date in the short span of time will be difficult.

Do anyone have faced similar situation?

Also if I process the H4 through a third party (Travel Agency), will there be any problem/issues?

If anyone did the same in the past, please share your experience. Thanks in Advance.