You can get good 1/32 drivers like the DRV8825 (https://www.pololu.com/product/2133 https://www.pololu.com/product/2133) for not too much - I'm pretty confident

You can get good 1/32 drivers like the DRV8825 (https://www.pololu.com/product/2133 https://www.pololu.com/product/2133) for not too much - I'm pretty confident they'll be able to do what you need (You can buy knockoffs for even cheaper). Even 1/16 is pretty dang smooth. It also might be that you're supplying too much or too little current to the motors - both will result in jerkiness and noise. If your current drivers are current limiting, I'd look into tuning that. If they aren't, the ones I linked are.