One more thing
 

Got C clips with rotating assembly,seems to easy.Spirolocks better?

You use what the piston has in it. If it is designed for "C" clips then you cannot use Spirolocks. You may be able to have them machined to accept Spirolocks. You use four locks per piston, two one each side of the pin. You can use an old pin to "tap seal" them while installing them. I have heard the Spirolocks are safer, less chance of breaking and tearing up the cylinder. I have used both, but the Spirolock seemed to lock more securely. JMO.