Hello there, I own modelart sandstorm RC truggy. It has a combined radio+esc unit. I want to change the esc as I want to upgrade to brushless motors. Can anyone help me out here as in what changes should I do in the most economical way?  *help*

If you want to seriously make it hobby grade , then you will have to spend atleast 6-8 k
First you will need a proper transmitter
Second a good high kv motor
Third a good car esc with reverse
Fourth a proper high torque servo
Fifth a lipo battery for all this

I have a Wolfpack 7.4 v 13000 Mah 25C 2s lipo, for the motor, I have this great confusion about which brushless motors will match with which sort of esc 's ,and for changing the esc, again I haave to look for the radio accessories as it's 2 in 1 unit

And again, if I change the receiver circuit,then the whole transmitter dps setup that I already own will become useless?