First, examine the undersides of the rocker arms where they contact the valve stems. It's pretty common to find them worn concave so it's difficult, if not impossible to get a good adjustment- - - - with solid or hydraulic lifters. Yes, hydraulics should give virtually silent operation, as long as they're in good condition and adjusted correctly.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!