Put it where it is easily accessible; don't have to think about reaching for it, it should be instinctive. We prefer our drivers keep one hand (the left hand) on the wheel at all times and make all actions with the other like launch control, shifting gears and the shut-off lever. I understand that there is not much room for too many things in one area, but switching hands on the wheel during a run creates an unnecessary action and is not optimal.
The cable can be fasten with cable ties, but better to use Adel Clamps to ensure no slippage.
Use and push/pull transmission cable with an open end and ball link in the other. It is better to push than pull the lever as you can slap at it rather than grab and pull.
Get a cable from these guys:
http://www.power-trans.net/