What's the minimum focus distance on your 200mm? I'd try to find ways of getting closer first, and then maybe try the TC if you still can't get close enough. A TC isn't a panacea, and will cause some degradation in image quality and take your maximum aperture up to f/4. The lens/TC combo probably won't reach best performance until you stop down to about f/5.6.
I use a 1.4 TC on my 80-200 AF-S from time to time - the results are pretty good, but not really on a par with the bare lens.