Rhyzm

Hey, just recently got back into rc hobbies. Picked up a nice 2wd short course truck and wanted some upgrade suggestions. I want to race a little and also bash with some friends so it needs to be water proof. The motor is rear mounted so im not entirely sure what size can or what motor KV to go for since I see a range of people saying stuff from 3000-4000Kv. I liked the hobbywing max10 and max10 sct stuff but wasnt entire sure what to buy. Working on a budget of 150$ Also if you have other suggestions or setup sheets please feel free to send a reply. Also if anyone has ideas for what gearing to do it would be helpful. I have a Hpi Blitz if that helps, thanks.