In both sports and entertainment the "agent" model works because the person being pursued is considered highly irreplaceable (like Kobe Bryant or Angelina Jolie). For the team, players having agents is a huge negative. But what choice do they have? People are only willing to put up with a bad process when they feel that they are getting something invaluable. That's why people line up out the door and around the corner at special food spots like Georgetown Cupcakes, or for a cheesesteak in Philadelphia.
In other words, even though I agree that some developers are so highly skilled that they are essentially invaluable, if you walked into a company with an agent they'd simply put your resume aside and find someone else. Programming (especially in the eyes of the non-technical) is a highly replaceable skill.
I don't think we are talking about W2, full time lifetime employment here. (If we are, I agree with you)
If we are talking about short-run gigs, it is completely normal for consulting houses (body shops, whatever you want to call them.) to have salespeople. Hell, I've played this roll myself. I mean, I was not very good at it, and at this time, I don't really want to reprise that role, but I could. Setting yourself up as an employer isn't hard. Getting on prefered vendor lists can be, but you can work for smaller companies without doing that part.
The problem is that usually? in that role the sales person is seen as being more powerful than the worker. And in the employers eyes, this is required. That's not the problem; the problem is that everyone that does this acts like they in fact have more power than the programmer.
(Oh yeah, the role here? the body shop. I've worked for body shops that had one guy, a salesguy, essentially, and then a bunch of contract workers like me. I remember this one guy; best body shop I worked for- he always paid on time. But he didn't keep anyone on staff. When one of his customers wanted a body, he'd put an email out to his contacts, or failing that, an ad on craigslist.)
so how do you restructure this relationship so that the programmer has more power? I dono. Difficult, as by definition, the salesguy is a better negotiatior.
In stark contrast developers are engineers, i.e. they make something that's a result of a specification. Now yes some developers are better than others, but that work is "under the hood".
Now an exception to the above might be a "rock star CTO" or founder who is really more of an architect or a product person. But at that point their actual code is besides the point if you know what I mean. In fact the actual code from this sort of rock star might even be below average, but that's not why they're getting funding.
Side note: In the case of an entertainment artist who has an agent it's the artist with the best track record that will do do well. An unknown artist with an agent is still at the bottom.
However that set of actors is a small sub-set of those actors who get a role every now and then but don't earn a full time living. So there is an entire class of actors who get an industrial spot, do summer stock, play an extra or do voice overs who don't have an agent.
I know this because I've hired those actors for various projects. However if those actors had a name that you could recognize they'd have an agent.
Ed is probably the closest example of this idea I've seen; recruiters don't make as much money from freelance referrals so if they do this at all, it would be sparing.
Cool idea though. I'd be interested to see if it works out in an explicit fashion as OP describes.
What you do need is good connections/contacts which unfortunately only comes with experience and meeting people on your own. If at all, I would say try finding a mentor or someone like that.
Some possible payment models - a) a percentage of the successful position. b) an hourly rate for doing the task of job hunting. c) a percentage combined with a one-off application fee.
Depending on your needs, you could probably find someone to help you out. Finding someone with a bit of legal knowledge and experience might be a good idea. Try putting an ad up-- I bet you'd get a lot of responses.