If you want classical music to play on the guitar, depending on what level you are, paganini...any of the caprices, esp. 5 and 24.
A lot of vivaldi's technical 'stuff'/runs from the four seasons can work very well on guitar, esp. Winter
If you actually want classical music written for a guitar though... which i think you might do based on the classical/acoustic bit, then erm, damn, sorry