There are MANY variables to consider when choosing.
1. What surface will it be sitting on? I have the old steel quad pod version but had to also get a set with a flat plate base since my driveway is asphalt. The legs of the quad pod will sink into the asphalt if you leave weight on it for long periods.
2. What lift points will you be using? If you're lifting from the frame, you'll need taller jack stands. If you are lifting from axles or suspension arms, you'll need shorter ones.
3. Get them plenty strong. As you are jacking the vehicle up, the majority of the vehicle weight can shift to a single jackstand. Once in place, the weight should distribute evenly though.
4. A wide base is better for stability but makes the jack stands more difficult to store when not in use.