The size of the guitar to use is best detrmined by the "scale-length" (distance from the Nut to the top of the "saddle) - the little white strip which is placed in the bridge of the guitar).
The current "standard" for classical guitars not made by hand (luthiers) is 650mm or about 25.6".
If your fretting-hand "spread" (from the little finger to the thumb) is under 9" you probably could benefit from a "shorter scale" guitar.
Some makers do make them with 635mm to 610mm
and often labels them 7/8 size.
Within the "student-level" instruments "Strunal"
Makes a 620mm, Takamine makes a 628mm and Giannini
makes a 610". The last time I checked they were under the $300 price tag.
