Details (subject to change)

For the sake of some people who are too cheap to phone up the suppliers and ask for price lists, this is what we have spent _so far_ (in order of cost):

A quick run down of each component then:

Vantec RDFR33 Speed Controller
Probably the best series of speed controllers you can possibly get the RDFR Director will take virtually anything you can push through it.  It mixes two channels into tank style steering and you can customise the ramping to suit your needs - just by moving a jumper.  Brilliant!  See links below for more information.  They are quite expensive, though.  And you could probably do the same thing with two 4QD speedos.   Although you have to add some more components and that would end up costing more...

Sinclair C5 Motors
These are total brutes of motors.  .12V, 29A of pure power.  348W to be exact.   Turning in at 3300rpm we've had to put the 5:1 and then a 2:1 chain onto them to bring it down to 330rpm, and even that is damn high - and it will be putting out about (.4664879 x 5 x 2) 4.7 horse power - assuming of course, that the motors are 100% efficient.  Which they are not.  The 5:1 gearboxes are out of a C5 and put out to a toothed spool designed for a timing belt of some kind.

Hi-Tec 4 Channel, 40Mhz Digital Proportional Radio Control System
A very nice four channel transmitter and reciever configured for aircraft use, so we can use the Vantec to control the robot with one joystick and then the weapons with the other.  There is also the option of "daisy-chaining" another transmitter in trainer mode, just in case.

4QD Series Speed Controllers
Not actually used in Mercenary, but seriously considered.  These are more the bare board type speed controllers.

Features:

• Bodywork can be used as a weapon in event of weapons failure, or rear attack  Made from [censored], used extensively in armoured cars. This material is virtually impact proof and will take a fair bit from a chainsaw, and even comes with an "indestructable" guarantee from the manufacturer!
• Light, and therefore fast so running away is possible in extreme circumstances.
• No hydraulics (as of yet) - so we can't get paralysed by one carefully aimed blow to a hydraulic line, a la Thor and The Master.
• Low ground clearance, can not be easily flipped over.
• Dual speed control so it can turn without stopping first, enabling faster evasion and greater manoeuvrability at speed.
• Zero turning circle.
• Looks cool.

Vantec info: