Nipple piercings

I'm getting my nipples pierced sometime in the near future. I have a couple of questions.

Should I get the straight barbell or should I get a horseshoe barbell?

I don't wear bras will that help the healing?

My boobs are rather uneven to the point where it's noticeable. Will that effect the piercings?

I have a pretty good success rate with piercings. Is there any issues that only really happen with nipple piercings?

Anything else I should know?