Hi
The dry ice blaster is great! I hope to get a guy out selling services soon. Got to clean up our equipment first though

You would want to use a 3/4-1 " crushed limestone for a parking lot if you aren't going to pave with asphalt or concrete. If he is going over just grass to start you are going to need to put 6" down. This rock will get beat down into the dirt/grass and you'll have to add another inch or two next year. Something a bit more permanent would be asphalt millings if you can get them. Spread out and rolled they will tend to become a semi permanent surface in the heat. Texas heat would really activate those oils and get it to set up. Hope this helps.