Here is one option for a Light Mount: The Command Arms Accessories (CAA) “M4 Front Sight Mounted Dual Rail”. 2.5" polymer Picatinny rails attach to front sight via Allen bolts. (Optics Planet / Botach $27+).
Check out impact weapons components, they make several mounts that attach to MOE hand guards and have some package deals.
Other options would include a rail mount light (X300 or TLR1 or similar) mounted to a midwest industries FSB mount, mossie tactics FSB mount, or MOE rail attached to the hand guard itself.
You should click the link he posted (you probably couldn’t tell because it was underlined text which means it’s a link in web format) that is a sticky at the top of this forum.