I've had good luck with GoolRC motors, you can save some cash here:
https://www.ebay.com/itm/GoolRC-4268...kNis:rk:2:pf:0
As far as ESC's go, I have learned that HobbyWing is the only brand I can rely on, trust me, I've ran maybe a dozen different off brands across the net and when it comes to ESC's, you will get what you pay for... if cash is tight and you want to save up for a HobbyWing down the road, then I would consider this combo here just to get you by in the mean time, but don't expect it to last long term:
https://www.ebay.com/itm/Original-Go...UE1a:rk:5:pf:0
You will still hit your target speeds on 4S, but expect to peg your temps, I would consider investing in a cooling fan for the motor to help buy you some more time on it.