With the kit that TRZ and I are working on!

Nah there are actually several ways to do it and they all will work pretty well, I just like the way TRZ did the one in my car (and its the same in Mitch's, Eric Kenwards Wagon and Malibu and Chad Henderson's Outlaw Radial cars as well so you know that it will hold some serious power).
We are just trying to figure out how to come up with a kit that will be easy enough for the average guy to be able to install in their garage, but have options that will work for those that are building a more serious car. The picture below shows a crossmember that welds into the chassis, then a brace that goes around the bolt hole for the lower control arm. The brace that goes upwards off of the crossmember goes to the upper control arm mount. Beefing up the lowers like this is real easy, but doing the upper support like this means you will either have to cut the floor or cut out the floor and move it up like I did on my car. The main hoop of the roll cage lands on this crossmember in my car as well.