I have cycloops alum cylinder rollers, they work great. Rollers do have quite the learning curve though, I'd personally only recommend if you already have a turbo and want to focus specifically on balance, as you'll likely get a better workout on a turbo, be able to watch some TV, not have to find the tiniest hallway possible, and not have to try as hard as possible to stay on while drinking from your water bottle.

Also, by "better workout" I'm referring to having the capability of sprinting out of the seat and finish workouts even when your form slacks a bit.