You can use any glaze you like on top but keep in mind the translucency of the glaze will affect how much of the design you see. Even some clear glazes can appear cloudy or milky when applied too thick so consistency is also a concern. I recommend experimenting with some test tiles to get the perfect glaze before glazing a bunch of work.
I use Cone 5 HF-9 clear zinc free glaze from Amaco (it fires well to cone 6 too). I buy it in premixed gallons so I can brush it on each piece and I fire it to Cone 6 with a 5 min hold at temperature and a slow cool of 150 degrees per hour until it reaches 1800 degrees and then I shut the kiln off and let it cool naturally until about 200 when I crack the lid to peek.