No, no, no. You're overthinking this and confusing yourself. You don't say "a Choice Specs" you just say Choice Specs. As a singular item, you'd say Choice Specs is an option, and as a plural, Choice Specs are items.
Singular: Choice Specs makes Celebi powerful, just like a fez makes Celebi look cute.
Plural: Choice Specs make Celebi powerful, a pair of Choice Specs makes Celebi powerful, a pair of Choice Specs make Celebi powerful (either is acceptable).