I'm using the same 20g Zippys, levered in this case, on my Ultimarc T-stiks (aka IL 4-8-Way; they are the spring version of the Magstik. The T-Stik/Mag-Stik is probably the 'stiffest' and 'clickiest' of all switch-based sticks in stock form.) I modded these sticks with weaker springs and the afore-mentioned 20g switches with very good results, and haven't had any durability issues to date.
I'm not sure that you would need to go to a switch quite so light on a Eurostick as the feel on them is so much lighter in general, but if the clicking drives you crazy they are a valid option.
Good luck!