RE: Do wheel brakes exist for trainers?
No offense, but it just sounds like you need to practice landings a bit more. You shouldn't need breaks on a trainer. You might want to look at your landing speed, your throttle setting at landing (should be at idle), your idle speed might be too high, and you may be landing a bit too far down the runway. When I was learning on a trainer, i used to put in at least 20 takeoffs and landings on a tank of fuel, and I would practice hitting my aiming point, and landing smoothly on the centerline of the runway, regardless of wind direction or conditions that day. keep practicing!