My struts were shot when I got my Special. I agree they make a massive difference. So much so that I'd like to do something similar for the front bonnet too. I'm sure I've seen a car with hydraulic struts on the front bonnet too somewhere, on the site, but can't find it again. I think it was just in a photo, not detailing how it was done.
I didn't have the prop (stay)for the front bonnet and the one I got from Lotus Supplies is designed to pivot from the lhs not the rhs, so it pushes into the hole in the bonnet from the outside, instead of the inside. I don't really love how much the bonnet flexes about just propped.