To make a selection based on your approach would require knowledge of the spring rate of the Calmini springs, and all you can give us is the free length, which, by itself, tells us very little about the spring.
It is possible to replace a long spring with a shorter spring and end up with increased ride height if the shorter spring is stiffer (has a higher spring rate), the converse is also possible, you can replace a shorter spring with a longer spring and end up with a reduced ride height - spring rate is a critical factor when selecting springs for any application.
I think I should point out here that the way Old Man Emu markets their suspension is distinctly different to how most other off road suspension manufacturers do - they will rarely offer springs for a specific lift or height increase, instead they specify their springs based on weight - the additional weight you anticipate carrying in the vehicle, and they design their springs to take the additional weight without sagging - the springs do give a moderate increase in ride height (about 30mm), and the stiffer springs will give more lift in an unloaded vehicle, but this comes with the disadvantage of a rougher ride.
Given the fact that properly selected OME springs are known to lift the vehicle about 30mm, the longer stiffer spring should give you a little more than that, so if you want to give them a try, that's the one to go with.
There are several other spring manufacturers who offer springs for the Sidekicks - Dobinsons (of Australia) have a presence in the US, and I believe Ironman (also of Australia) - you can try contacting them and asking how much lift their springs will give you.