Two fast and powerful servos. Any suggestions?

Hello!
I need two servos about 15 kg.cm. And 0,10 sec/60 or faster. Also I need to modify them, for 360 continuous rotation. $40-60 for each. Any ideas?

It would be great if together they consume not more than 5A on start and work with two 3.7V Li-ion batteries.

What are you using these for?

It is a simple project - a focus system for a taken lens and anamorphic adaptor. I have three pots. The first one I use as a manipulator. The second is used to get the position of the continuous rotation servo motor#1. The third pot is used to control the position of the other continuous rotation servo - motor#2. Motor#1 rotates the taken lens and motor#2 rotates the adaptor.

Old lenses are very stiff. I've tried Doman, but it has problems with CCW speed, then I've tried JX, but they consume to much current.

By the way, what do you think about JX coreless servos like PDI-HV7223MG?

Hello!

I've found these three servos:
XQ-S4116F
Vortex VDS2-HV 1605
KST BLS915 HV

Which one would you recommend for my purposes? Can all of them be modified to multi-turn servos?