You'll have to go onto FISD for all stormtrooper requirements. You can have the Commander paintjob from Force Unleashed, but no weathering or custom paint. Here is he link for all the Stormtrooper standards.
If you wanted to go sandy on theother hand you'd just need to remove the pair, or alternatively get another set of armor for the bits you've painted so you can wear your custom one at non cannon events.