I was a host for a number of years in Vegas...
In general, host's come up thru table games department. If you looking to start out as a casino host from never working in a casino you can forget it unless you got some serious juice. On the strip you prob would start out as a 'cash' host, meaning you have no credit authority and prob be making around 30-50k a year at the better places. That's in domestic marketing not international. Credit hosts can make up past 200k and bonses....but its up to how you produce. International marketing people can make a whole lot more, so if your asian especially that's the ticket.
Outside hosts as you call it are called 'agents', and to be an agent you need to get your agent license which in vegas means filling out a big stack of papers, having an interview with gaming agent, and getting your sherriff's card. Then if you get on an agent list of a casino (some don't use outside agents, others do) then you can send customers and get a piece.
In either case if your coming into this cold then you got almost no shot..try working in an outside marketing office to start or go up thru the old way of being a casino guy, or find a bigshot with juice to land u a job.