Friz:  Here are my observations for you:

1-Take 500 more rounds of ammo that they tell you to.
2-The more magazines that you take, the happier you will be.
3-Invest in a Camelbak hydration system, it's a must have item.
4-Take knee and elbow pads.
5-Do more and say less!
6-If your lodging in Kerrville, leave the hotel super early, it's a long drive to the ranch.
7-If your staying on the ranch in the cabins, check your boots and bed for scorpions.
8-Take some Power Bars to eat throughout the day to stay "carbed up".

These are my observations.  You will receive the best training that your money can buy.  Good luck and stay hydrated.

Friz:  I just noticed on your initial post that one of the classes was the defensive shotgun.  Well 500 extra rounds might be excessive, but 100 would not be.  Have a blast, and you will enjoy those black granite ranges in the hot April Texas sun.  I went in August and got way too dehydrated, but survived.