There's also the 949 6UL:
http://949racing.com/15x7.5-6UL.aspx
Just a bit more than the others, but available in 7.5 wide which is a big benefit for autocross. You want all the wheel width you can get.
I'm waiting for the konig hypergram. 15x7.5, +35, flow formed. Discount tire should be able to get them fairly soon. If you're open to second hand suspension, I've got RB springs, CS adjustable front struts, and bilstein rear shocks for sale.
I don't really like the style of the 6UL's. They look better on an older car. The futuristic style of the Mazda2 does not match it in my opinion. I do intend to be competitive.
I'm actually looking at the CS adjustable struts and shocks with CS springs. They are being sold as a set discounted at $540 total + shipping.
Locally maybe, but you'll need double to triple that spring rate to minimize roll and ultimately remove the front bar for greater off corner acceleration (aka reduce wheelspin)I do intend to be competitive.