Hi, Randy
None of the melodicas that I have played (about 15 different ones) are weighted or have the resistance that piano keys do. The best I have played is the Hohner Professional, whose keys are also larger. The Yamaha 37 has the smaller keys, but does have pretty good “feel”. Also, the Clavietta has adjustable spring tension, so that may help you as well.
Just some thoughts
Regards,
Shannon