Go to IOA! I am exactly like you, I don't like rollercoasters or flumes. Actually, I hate rollercoasters and flumes.I just do not like that feeling at all, but I think you'll be fine on Spiderman. I really enjoyed that ride, didn't have the same feel to me as a rollercoaster.
Even non-coaster/flume people like me can enjoy and fall in love with Universal/IOA. I hope you have a great trip!