I put a FlySky GT5 radio system in one of my trucks and am happy with it. (About $60 on Amazon).
https://www.amazon.com/dp/B0CKWVVRCR?psc=1&ref=ppx_yo2ov_dt_b_product_details
There are lots of ESC/Motor choices, Hobbywing gets a lot of mentions here, but for a 1/10 buggy, the 140A might be a...