I've not read of many who have used the LED ringflashes, though I got the feeling that they were not quite as powerful as many would hope when compared to regular flash units. (its just an impression though, I've never had the chance to use one to really know).
As for which items would work best, if you can get a set of 3 extension tubes which retain electronic contacts within the setup so that you can maintain control over the aperture would be ideal. I've read some decent reviews of the cheaper Zeikos ones that you link to, though there are also some who have experienced problems with them sticking to lenses. Kenko are the most popular brand name for extension tubes, though a full set is going to cost you more:
Amazon.com: kenko dg auto extension tube set for the nikon af mount
Ebay might have some shops selling cheaper than Amazon, plus you might find some selling them second hand at cheaper still if your budget is very limiting.
As for the close up lens adaptor these are broken into two kinds, lowgrade single element options which work, but give degraded performance overall; and the higher grade multi element options which deliver a very high grade of results. The Raynox series are very well regarded and certainly worth considering as a high quality attachment.
As for which is best, I'd say the Extension tubes for your setup. The close up lens attachments work their best on longer lenses (ie give the most magnification gain) whilst the extension tubes are the opposite, giving more magnificaiton on shorter lenses. Your 18-55mm with tubes would probably prove to be your best setup; the 35mm is a bit short, which whilst offering good magnification with the tubes, will also have a very tiny working distance (distance between subject and the front of the lens).