#17 looks like a great product label (by the way, it reminds me that i would need a button design) but not quite as good for a site header
i would suggest elaborating more on #13, like changing the typeface to make it "cleaner" (keep your 'z'), also red doesn't look good to me, perhaps play with the background (but keep it in sync with the design)
#31 is good. couple suggestions though: pls fix kerning to make the word symmetrical (downward point of 'p' should mark the middle); the orange marks of ‘z’ do not work well, perhaps just make orange the upper bar of ‘z’
#64 looks pretty. however, on web page this foxy 'z' is not visible. overall look is kind'a unfinished.. perhaps would be better if you get back to blue