185/65 is more suitable for 175/70 replacement, but you would loose some 2 mm GC. With 185/70, GC will increase by some 6-7 mm, but there will be big speedo error.
My view, considering VFM factor, stick to 175/70, take michelin 4 tyres. Keep spare in spare to use in emergencies only.
Otherwise, if money is not a factor, take all 5 Yoko A-Drive of 185/65 size.