As a summoner is there a specific gear set I should be aiming for?

any gear with tech, hp and pp is worth

Also, Harmonizers don't count toward your damage calculation.

saiki set atm, slave barl or nemesis for weapon and do your client orders from pietro for candy for candy box, also get his card and get 10 gifts from him to get the support roll and make another character to repeat that (getting 10 gifts from pietro for suppor roll) when your bored