THAT is well done, not overdone. Simple, light, effective.
Don't think that it being simple and not overdone is on purpose. . . It just means the money ran out!
Next:
Rail panels
PMAGS
LaRue Optic Mount
Tape switch for light (or possibly go in another direction. . who knows)
VFG
CTR stock (I HATE how sloppy the M4 stock is)
Anyone else ever notice how every single add-on part for ARs tends to be somewhere between $100 and $200? Sheesh!