Boy, did you ever walk into a minefield... While I hate to sound like I've got an ego (who me?) I wrote an article a number of years ago about all the things you need to do to the Lindbergh kit...it's located here:
http://www.steelnavy.com/BDFletcher.htm
Recommendations about the Lindbergh kit...give it to a neighbor kid and go out and buy the Bluejacket 1/192 Fletcher if you want an accurate one. You've heard they're bad, well, you're right, they're bad. As for aftermarket, the only stuff out there are the white metal 20mm and 40mm AA guns from HR Products, available through the Floating Drydock (www.floatingdrydock.com). The parts are a marginal improvement at best, and it takes HR centuries to get stuff to Floating Drydock.
Information about the Fletchers...well, there's a book out there called Warship Perspectives: Fletcher, Gearing and Sumner Class Destroyers in WW2, written by some fella named Herne...it has camo design sheets, detail photos, line drawings, and a complete listing of ships of the class, hull numbers, mods made to the ships (like Emergency AA fits and bridge types), and all sorts of trivial stuff.
As for Fletchers in the Aleutians...nope, sorry. Fletchers operated in the central and south Pacific with the carriers. By the time the Aleutians were secured, the Fletchers were needed elsewhere. I'm sure there were instances of one or two passing through the region while en route, but the Aleutians received many of the slower, older destroyers that weren't able to keep up with the task groups.
As for decals, well, all you'll need are hull numbers and draft marks, and those can be had in generic forms in various scales. The numbers should not be more than 24" high in scale...so you can probably get away with 1/48 USAF style numbers. No one does any that are custom, although you might be able to find some in a closer scale, say 1/96 or 1/100.
Good news is...if you're still deciding to plow ahead with this project...is that I can help you out, having been there, done that, and bought the T-shirt. Tom's Modelworks is also preparing a photoetched detail set specifically for this model. It's to be a limited run, so you might want to contact him if you're interested in getting one.
Hope that answers your questions.