Might be a plan to measure the thread diameter with a vernier as there is not a 20mm size.
Also you get different size of seating cones as well.
Are you replacing the lower arm as well?
Best to get your multi meter on it to check for feed at the actuator.
Another forum member had this issue recently and it turned out to be a switch issue.
Like for like is best.
If you fit it straight from the factory then expect to get 10 years + from it.
If you give it a coat of rust protection then it will outlive the car.
Plenty in stock if required, treated or untreated.
You wont go far wrong with Yokohama A052.
I run 235/40 18 and 265/40 18 on OEM Rays.
If you want to go the Federal 595 RS-R route then I have a spare new set in stock, same sizes as above.
I have a full kit in stock including the intercooler and associated pipework.
Do you also require engine tuning/management stuff and gauges or are you going up rev?
Do you also require an uprated fuel pump and fuel return system and injectors?
Everything in stock and good to go same/next day.
Just let me know what you require here or by PM