H1B Visa revoked.

I got stamped H1B last year from Chennai consulate, and could not travel to US due to personal reasons. My US employer informed USCIS to revoke visa, and I can see the current status as ‘revoked’ in USCIS site. I have contacted two companies/consultancies who are ready to transfer my visa with paying some money (3000$).

The confusion is , the company A told me that they will file premium processing and I would get I797 in 30days and eligible to travel with new I797 immediately and no need to go for stamping. But the company B told that they will also file premium processing, but I need to go stamping again. I 'm really confused on what is right and wrong. My visa will have old employer name if I’m not stamping again. Could anyone please help me on this?