You shouldn't go by what others use. You should calculate what you need based on the weight of your hood. You'll need three measurements.
Pick a mounting location for one end of the shock in the engine bay (A). Pick a mounting point for the other end of the shock on the hood (B).
1. Measure A to B with hood in fully open position. This is the (minimum) extended shock length.
2. Measure A to B with the hood closed. This is the (maximum) retracted shock length. (This can take a little creativity to measure).
3. Weigh the hood at point B. This isn't easy. I normally use a broom handle under the hood located at point B (from point B on the left side across to point B on the right side of the hood). Put a bathroom scale under the center of the broom handle with a block of wood supporting it on the scale. The hood should be as close to the closed position as practical. Hopefully you can read the scale. Divide this number by 2. This is the minimum value for each shock. I like to add about 10-20% to ensure a solid lift without it being too difficult to close.
These three values give you everything you need when you go shopping for the shocks. You may need to play around with the mounting points to optimize the values and match available shocks.