Yes, this class is treads only. It has been Hoosiers only the last few years, but their pricing is getting out of hand. The track is allowing Maxxis and Hoosier treads now.
Track is typically hard packed and dusty slick.
I would go with Burris tires; we ran Hoosiers on our lawnmowers and never could hook them up. The Burris to me a much better tire. I can give you a few contact numbers where we got ours at a good price.
Stay with Hoosiers. The Maxxis are a synthetic tread version of the Whites. Unless you are allowed to prep them extensively, the Hoosier D20A treads will make more bite because they have natural rubber in them. (That is another reason they are considerably more pricey right now - natural gum rubber has gotten crazy expensive, and shipping from South America hasn't gotten any cheaper.)