Powerhobby 729MbL all the way. You'll never need to replace it. Run it on my 6s EXB for 3 months with no issues. Set your voltage on the receiver to 7.4v instead of 6 in the ESC settings.

https://www.amazon.com/dp/B083Y4QKZF?psc=1&ref=ppx_yo2ov_dt_b_product_details

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Or for a budget. Get a JX Ecoboost Servo 35.6kg