^Sandstorm only lowers the accuracy if you attack some pokemon who has Sand Veil as it's ability. And actually, Hyper Cutter is better for sweeping Gliscor ( unless he has Sandstorm support, which you don't seem to have), since you don't want your attack do be lowered.
And yeah, Starmie would make a good adition to your team. Try something like this
Starmie ( Modest / Timid ) Life Orb / Wise Glasses / Choice Specs ( yeah, tons of options )
Ability: Natural Cure
-Surf
-Ice Beam
-Thunderbolt
-Grass Knot / Psychic
Recover could go on the last slot if you're using Life Orb.
And yeah, Starmie would make a good adition to your team. Try something like this
Starmie ( Modest / Timid ) Life Orb / Wise Glasses / Choice Specs ( yeah, tons of options )
Ability: Natural Cure
-Surf
-Ice Beam
-Thunderbolt
-Grass Knot / Psychic
Recover could go on the last slot if you're using Life Orb.