High power servos advice please

[rsj]

Hi. Couldn't find much out about this but I'm looking for a high torque servo which I can power direct from 2s lipo rather than from the Bec supply from my esc.
If this is already covered somewhere please point me in the right direction as I couldn't find it.
This is the first quality servo I will have bought and am finding all the choices and specs hard to sort through and some of the manufacturers I've found I've not heard of before, mks XQ etc. Servo is initially to go in a DEX410 so needs to be standard size.
I know a lot of people reccomend Savox for value, I looked but their 'standard size' High voltage SC1267/8sg's are 48mm long so won't fit.
Spektrum S6090 or S6100 both run 7.4v have steel gears and seam reasonably priced at £70-80.
KO RSX Responce/Power will run 7.4v but are too expensive for me.
Can anyone suggest any others look at or any other advice?
Thanks in advance.
Jools