Hey guys..I'll try and help with your questions. In no particular order...
(1) I saw several IM people on the interview trail (more than psychiatry, actually) and they seemed to be as competitive as Dr. Rack suggests. I frankly wouldn't be surprised if there were an increase in the number of IM applicants accepted in the future (particularly to pulmonary-run programs) as more and more pulmonology fellows opt out of that additional year of fellowship.
(2) I'm a neurology resident, so I cannot comment with authority on the practicability of being an IM hospitalist and running a sleep practice on the side. But in the world of common sense...it seems to me that it would be perfectly feasible if your IM group wanted to structure things in such a way. Why not? A sleep lab could help them in a financial capacity. Now, if you wanted to set up a private, independent sleep clinic in addition to working in an IM group then I suppose that is also feasible...but would take a great deal of effort (and money) on your part.
(3) Research is always a plus for attempting to land a more competitive fellowship. This goes without saying. The topic or "field" (I assume you mean subject matter in terms of pulm v/s neuro v/s psych) is completely up to you, a sleep program, or the attending you work with. Or the availability of actual sleep research at your home institution.
(4) What makes one competitive for a fellowship from a general standpoint is an extremely variable and well-discussed topic on all of these forums. The search function is your friend.
Briefly, great letters of recommendation, being able to pull off a strong interview, coming from a well-regarded home institution, and research are four great locations to start...
(5) I don't know of any programs that are specifically "friendly" to IM applicants. You'll have to look around for those yourself and perhaps others on these boards can comment further.
Best wishes.
