Good BL System

So i had my heart set out on the HV 6.5 for a little bit now and was pretty sure i was gonna go wit it...until i heard people say it is not the best way to spend $300.

so, $300 is my MAX budget. im going to be running EP 4200 7 cells. I alwso want a system i can drop in there, mainly the motor, i can deal wit finding a mount for the ESC. Im very new to BL systems so i get real confused when people talk about neu and fiego?...
i will be doing mostly bashing and i would like a top speed of 45+

I was hoping someone here would know waht set up i should go with with my budget. I heard yall were the best to talk to about this. Thanks