See - for servo, I used a stock traxxas 2080... it's the servo found in their "mini" line of truck (1/16) and it works pretty good.
However the servos you're posting are servos that are usually used in 1/10 RC... so you'll have plenty of torque, but space might be an issue.

I would stick with the trackstar for 2 reasons:

1- Other people have used it and have "confirmed" it can be placed in the truck somewhere to make it work
2- It works with lesser voltage that the HV servo you found on banggood.

The servo you found on banggood looks like a crawler servo - it's meant to be plugged directly into a battery or at least used with higher voltage. If you look at the operating voltage for both, you'll see the trackstar works with 4.8V to 6V and the HV between 6V and 8.4V.

The 4.8V to 6V is a more standard operating voltage that the other one.
Usually BECs in ESC are outputting between 5V to 6V to other electronic components in the RC... having a servo that's asking too much voltage will "starve" the other components in your RC and you'll experience "brownouts" (couple of seconds where the RC is not responding at all). This is usually due to the receiver not getting enough voltage to work properly and loses the connection with the transmitter.

You can definitely go with the banggood servo if you like - but then I'd suggest looking into external BECs that can output the proper voltage for the servo ... which will completely bypass the ESC and receiver and feed the servo directly off the battery.

***EDIT***
I'm going back on the "crawler" servo... it doesn't have near enough torque to act as a crawler servo... but it has a high operating voltage (which is something usually found in crawler servo).  You're better off with the trackstar, it has more torque with less voltage

Edited 1 time by fullmetalsam Oct 21 15 11:00 AM.