Although the Pilot Powers look great, their availability is just starting to come around.
You'd be better off getting what is readily available in a 180/55.
Pilot H2, Pilot Sport, Pirelli Corsa, Supercorsa, are all good tires and are availible in multiple sizes/compounds.
If it's you're first trackday, it's unlikely that you will be pushing at a speed that will test your tires to the point that you'll need ultra-trick track tires.
I'd reccomend a good set of street tires as they will come up to temperature sooner and will likely be more forgiving if you start to push harder during the day.
Your suspension set-up will be more important than your tire choice as far as feeling comfortable at the track.
Good Luck, and ride within your limits.