I've searched but can't find the information I'm looking for. What is the best style?

I only drag my car...no autocross. I want the best stiffening qualities possible. Clearance is also somewhat of an issue.

Sell me on what style I should be looking into.

 

They all have pro's and con's.

Taken from ThunderRacing's website: "If strength is your number one priority, choose the boxed design. Boxed tubing is torsionally stronger than round tubing however you will lose approximately 3/4" of ground clearance when using this style. If your car is lowered and ground clearance is the prime concern, go with the tubular model. While round tubing is not as strong torsionally, there are other features to these subframe connectors that make them more rigid than most other tubular models available."

"When you install a set of Kenny Brown subframe connectors, you will notice the difference before you even leave the parking lot! With the original Double Diamond design, these subframe connectors reinforce the floor pan for superior strength and support by connecting the front subframes, rear subframes, rocker panel, and transmission mounts, while reinforcing rear lower control arm pick up point. Helps fight engine torque, chassis twist and flex in acceleration, cornering, and braking. Kenny Brown subframes are plated with OE-spec Yellow Zinc to help resist rust for years of trouble-free performance. All Kenny Brown subframes are weld-in to ensure lasting performance! (From our experience, bolt-in subframes tend to slot-out bolt-holes over time, causing them to lose their functionality!) These are an absolutely awesome upgrade and the difference in ride quality and handling is amazing! "