How to switch 220 VAC? (Magnetic relay, SSR relay or triac)?
You need to provide more information about your load :
is it inductive or resistive? 
How much current does it draw? 
Also unless special case (inductive motor, for which this circuit is not suitable anyway), you may want to use a zero-crossing opto-isolated diac (MOC308x) rather than the random phase MOC3021 shown here. 
Last point, triacs are great but heats-up, so unless your load is very small this heat has to be accounted for and dissipated properly.