If you’re also breastfeeding, stick to the Dr. Browns as they’re the best shape for a good latch. I exclusively breastfeed and used to give the occasional bottle but my daughter started using open cups and straw cups at 6 months. Sippy cups are no longer recommended due to impact on oral development especially if baby has teeth. I haven’t had to give her a bottle in a while but if I did, I’d give her in a straw cup. We’ve never used a sippy cup and she hasn’t used a bottle since around 8 months old.
Suggest you buy one of each and have your baby try. Never know what baby prefers.