The longer travel might not be better tho… Measure how much of your normal seat tube you have exposed, deduct about 50mm for the reverb collar bit and that is the max length of travel you should have. Ideally you want fully extended to be the max height you ride at. Depending on frame set up, length of legs etc, a long travel reverb, even if slammed into the frame, may extend too high and is a pain. Yes you can drop it slightly, but it’s fiddly and never a consistent height.
You could go shorter travel than this figure, as you can then leave some of the reverb post exposed out of the frame but, depending on how much you need, it might mean you can’t get the seat as low as you’d like. Make any sense??
Have a measure of your existing set up, take the reverb collar into account and you should figure out the ideal length…