Go to a GS program with an inhouse independent plastics fellowship. I would give preference to places that have integrated spots and independent. Then do a good job working in the GS department and maybe do a researc project with the plastics folks. If a spot opens up in the plastics integrated program (unlikely but occasioanally happens) then youre an inside candidate and they get preference. Ive seen this happen, and ACGME new rules state that you can only transfer out of general into plastics these days if its at your own program, cant change Universities to fill a spot until youre done otherwise, as I understand it.
When youre applying for fellowship being from a place with a program increases your chances there and also means you will have letters from people who are known by other programs. Letters from plastics people who faculty know matter infinitely more than letters from general surgery chairmen who they have only heard of or whatever. Good luck.