due to wrist injury, i am unable to hold up a camera much bigger than the SL1 for more than a few minutes, not long enough to track birds in flight. i'm wondering what kind of tripod head is recommended for this kind of shooting. at the moment i have no long or really heavy lenses due to wrist, so my longest lens is the 55-250STM, but with the right tripod, maybe i could go longer and heavier. i'm unfortunately on a budget but would consider going used. a gimbal head or pistol grip head seem like they could have advantages, but i'm not using a tripod mount on my lenses at this time. i used to use a pan head, but am only now realizing how crappy it was. suggestions?