hi
in simple way use 2 ic's 555 first one in stable mode to get long period 15 sec..
that triger second timer in monostable mode number of rotation here depend on
pulse width of monostable circuit ... abt drive stage for motor u can use any
general pourpese e-mosfet like IFR740,IRF840,etc.
but if u need accurate number of count then ...u must add sensore like microswitch or reed switch to detect number of count ..and its better to
switch to microcontroller.