You don't need those Special Dressphere.

Gunner + Trigger Happy + Cat Nip = Total Ownage. You get Cat Nip in Chapter 5.

Unerring Path is the best Garment Grid if you want to use Special Dressphere. Or if you want a good GG, Highroad Wind, The End, Valiant Lustre and Higher Power is the best. All of them can be acquired in Chapter 5 except for Highroad Wind which you can get earlier in Chapter 2.