Trainer/sippy cup for baby who never took a bottle or pacifier

My son always struggled with bottles. We tried for 12 weeks, giving him a bottle once a day at least, and he would never consume more than an ounce in an hour with paced bottle feeding. I was tired of pumping, had developed oversupply because of it, so we just stopped doing bottles. Fast forward to now, I want to introduce sippy or trainer cups. I bought the 360 miracle cup. We’ve tried every day for a month, and it’s still really not working. Any recommendations for a good trainer cup in this circumstance?