I guess, you want to use MOSFET instead of IGBT due to much better efficiency for low voltage applications. A series inductor is not necessary required, motor choppers are often working with the armature inductance only, although this causes some extra losses. If you want add an inductor, you'll calculate the inductance based on the acceptable current ripple.
Hi adi
An LC filter is optional ! but i'm using that filter in all of my designs ! because it will have some roles : 1- it will avoid from created noises ( from core of your motor ) . 2-it will take average from your PWM , and you can be sure that any HF component can't go through your motor .
3- it will increase flexibility of steps of velocity controlling !
By the way , i think as FvM said you'd better to use mosfet instead of IGBT for this low power . because an IGBT will have constant VCEsat at maximum conduction but for a mosfet it will be as a resistance ( Rdson ) which is pretty low ! . and a mosfet can switch with higher speeds .
Best Wishes
Goldsmith