You will also need at least a 15.5 gallon kettle to end up with 10 gallons of finished product.
I brewed my first 10 gallon batch this past weekend on my single tier system
There wasn't too much trouble with grain. 22 lbs in the Gott. 15 gallons in the kettle was a bit scary. I did use a defoamer, but I did have a small boilover with the first hop addition. I boiled for 90 minutes. Final output to two fermenters was a total of 11 gallons of 1.050 wort. With losses in racking I should get two full 5 gallon kegs.