i want 23g but found a good deal on 29's....if it only takes longer, i guess thats fine...?
You're never gonna get that oil through a 29ga pin. If you do you're probably not going to be able to keep your hand steady while injecting because of the force required to push it through and you'll end up with some nice bruising and injection site pain afterwards.
Get 23 or 25ga pins for any oil based gear. And run your test at least 12 weeks.