Paint? Do you mean anodyzing?
The black anodyzing adds a lot of strength to the handguard. If you take a file to anodyzed aluminum, you can easily feel how much harder the black layer is.
You don't want to sand the anodyzing off before refinishing. That's stronger stuff than aluminum - don't waste it.
You got some excellent suggestions. Sounds like you use you gun hard, which is how it should be.
If you want to do a cammo job, you have excellent suggestions. If you want easy, try Rustoleum black high temperature spray paint for charcoal grills. Good to 1200degrees, it won't cook until your hands are burt off. It is not very solvent resistant or tough, but it matches the finish perfectly, and a can costs less than $4.00 and will last forever. Just re-apply as needed.
I would go for the cammo job... it would look good. Just clean the black with solvent and rinse with distilled water, don't sand anodyzing off.
Pete