Try Andy McDermott. He writes a similar genre. BUT he is nowhere close to Mat Reilly and Rollins. McDermott focuses more on the action rather than character building, and all his archeology finds just happen without any buildup.
Reilly and Rollins are the masters of this genre. Not to forget Clive Cussler with his original Dirk Pitt series.
Considering The Lost Symbol was a shit-tastic book, I am going to stay the hell away from Inferno. Don't want to waste money really, otherwise I don't miss any books of authors I've once read, even if the quality of their writing has deteriorated over the years.
Good choice. Great book.