stepper motor+driver+tip122
Microcontroller's outputs have their own lateches already implemented, so adding another latch (74175) "in series" with already "build-in" latch doesn't make much sens, unless you don't have enough pins and you use the 74175 latches as port exptension ..
TIP122 has internal base resistors and can be directly connected to microcontroller"s pin. Some microcontrollers to assert a "1" use internal weak pullup; in any case, adding 1-10kΩ resistor as external pullup (between output pin and +5V) wouldn't hurt and will only improve the way TIP122s are driven ..
First, make sure that at the current voltage level, say 12V, your power supply can supply enough current to drive this motor ..
On the other hand, increasing the supply voltage above the motor's rating can cause damage, so be very careful and if you do increase the voltage try to do it in steps ..
Regards,
IanP