I used the lever hand brake assembly from a old Ford Pinto to do the conversion in a fairly radical IHC Scout 800B. You could also use the Lokar aftermarket assembly.
BTW, the optimum location is on the left side of the driver's seat. This lets you hold the brake, operate the throttle, and shift from 1st to reverse all at the same time, if your caught in one of those 'challenging' situations!
BTW 2, Marine maintenance/supply places can make short sections of 'control' (brake) cables with whatever fittings you need on either end.
The lever hand brake is MUCH more useful off road than a "T" handle or foot operated emergency brake.