how hard is it to get a bid from dg or kappa?

Well there are 6 sororities, so you obviously have a greater chance of getting a bid elsewhere. But it's not some impossible feat. Plenty of girls end up in DG or kappa without having known many older girls prior to formal recruitment. That being said, it's pretty unusual for someone to end up in kappa or DG without having some sort of relationship with at least one sister. You'll end up happy wherever you get a bid from, 99% of the girls who accept bids love their sorority.

Do not go into recruitment with the mindset that you need to be in a specific sorority... It will ruin the experience for you. Everyone ends up in a place they fit in best, whether they realize it at the time or not. I promise you, each sorority goes out and parties and offers great friendship and incredible opportunities. Keep an open mind.