All of my kids were spitters....MAJOR spitters, but they gained weight and had no other issues. Since they couldn't tolerate the brand offered in rice thickened formula, doc had us make our own by adding a tbs or so of rice cereal to the formula he could tolerate. It helped a lot, but it didn't completely stop. In our case, it was just an undeveloped valve that resolved on it's own before the first year or so.
Make sure your doc rules out any other issues, and then stock up on burp cloths, bibs, and shirts for you! :)
I just have to add, after reading some responses, to do what is right for your baby and your gut! I have yet to meet a baby who is 'textbook' so don't anybody tell you that you aren't doing the right thing. Trust your instincts!
~L.