How to choose my servomotor?

[makia]

Hi all,

I am trying to make a sumo robot, with servomotors but i heard that they have less torque, and I don't know if the torque are really important for a robot sumo ?
Can I gain torque or speed unless my servos?
I was looking for a Digital Servos with a torque of 250 or 350 oz like this one(not digital) : http://www.miniplanes.fr/radios-servos-simul/servos/servo-hitec-hs635hb-pignons-karbonite-p-14610.html

or this one(digital) : http://www.miniplanes.fr/radios-servos-simul/servos/servo-ssv9764mg-9kg-pignons-metal-scanner-rc-p-15235.html

Please can you advise me ?  :'( (sry for m bad english Im french !!)

Makia

[Razor Concepts]

http://www.servodatabase.com/