I second the recommendation that you finish aluminum before anodizing. Polishing or shot-peening, whatever. Just make sure all the surface finish is the same. And be sure to have all the parts done at the same time if possible.
If you are going to anodize welded parts, use 5356 rod for filler material (rather than 4043). 4043 doesn't anodize well.
The best part about black anodizing is that blemishes can be repaired with a Sharpie.
For door handles, I'd recommend powder coat. I think you'll find that more durable, and it will hold up better over time to UV radiation.
jp