I had another reply but when CS server had problems I lost it.
The essence of that post was that our highly respected Tom has given us a link for smoking fish that link is:
http://www.3men.com/threemen1.htm I found this recently doing a search of all the CS forums.
There is also a book that I have used which uses a smoking method for trout very similar to the above link which you might like to have. "Smoking Salmon & Trout" by Jack Whelan. A new edition is available on Amazon and some larger outdoor stores, an older used version is also available, I would check abebooks.com for them.
My specific thoughts would be to use a small amount of apple or cherry, and with fish of that size it would probably be best to filet them before smoking for ease of handling etc. Smaller I would probably try to do them whole, head on. I have not done trout in my CS, but I did do them in my old refer with a hot plate. I am about to cold smoke a batch of pink salmon and I am planning on following the 3men link except for the temperatures to see how it comes out.
You can scale trout by running the sharp edge of a knife perpendicular with the skin from the back of the fish to the head, but I would probably just remove the skin before I ate it after smoking.
There really is not that much difference between the meat of different trout, but there is between where you catch them, water productivity, seasons, water temperature etc. That will affect the taste more than rainbow vs. lake trout.
Good luck