Is there enough I/O on an arduino to do all that?
PS/2 will need data & clock (and power & gnd)
the GPRS shield uses a bunch more,
serial LCD will need several more, if not some specific pins for I2S or SPI,
3x4 keypad will need 7 if done normally using the keypad library,
and SDD is another shield itself?
PS/2, LCD, keypad are all pretty doable, have to see which pins the shields require as dedicated and if there's enough left for the others, or if you have to start adding aux hardware, shift registers, etc. to accomodate the non-shield(s) parts.