I saw your post, and knowing what a problem reflux is I said to myself I have to reply.
My baby was born at 34 weeks. She had bad reflux, would cry all the time, choke and we were so scared! Breast milk was better tolerated, but my milk supply wasn't enough. We tried different formulas, the one with rice starch as well (that made her so gassy and constipated that she couldn't sleep at night), but what saved our sanity was Similac Alimentum. It is miraculous! My daughter smiled for the first time after we started using it. It is the most expensive on the market I believe, but is worth it! It is lactose free and predigested or something like that, so is very gentle on baby's stomach. I read some bad stuff about Nutramigen over the internet (like is linked to learning problems later in life), I don't know if it's true, but I wouldn't risk it. It is the equivalent of Alimentum, but from Enfamil.
I have also noticed that ready to feed is better than powder, but it's a matter of mixing it really well before you feed. I shake the bottle a lot.
Another thing that helped tremendously was to use Dr. Brown's bottles, not move her too much after she eats and keep her head elevated for an hour or so. I also don't put her to sleep on her back, but on her side.
My baby is 4 months now, we still use lots of bibs a day, but it is getting better each day and since Alimentum she is a happy spitter