It will be my pleasure to experiment further. Please rank at least one of my entries somewhere 1st through 5th: that will enable me to post additional entries to your contest while it is in this Top 5 stage.
#62, #63, #64 - these are structured more formally #58, but the symmetrical points do seem to make the whole thing more 'vibrant', as you say (I'm assuming you meant that rather than color specifically). #62 is just flat spot colors, #63 introduces a bit of gloss effect, and #64 further introduces a gradient to the sun - seems a little hotter/alive. Typically, simpler is better in terms of broadest application and ease of use across media, but there is nothing in the rules preventing me from providing you with a 'dolled up' version for web/screen presentation and the simpler one for other uses.
#65, #66, #67 - I like this one too. It's formal yet very friendly and approachable. I like the way the sun's contours work well with those of the wordmark portion of the design, particularly the curves of the 'S' and the 'y'. (Something else I notice is how neatly the center of the sun falls over the letters 'ra' - an homage the the sun god Ra.)