I would spend the extra $$ and get the Quark. I have both the 9920 and the Quark . If your spending that much on a system. Do it ight the first time. Quark Is way better, It handles the load of a monster truck much better than the 9920 in my expeiences. I overheated the 9920 much easier than the Quark. I started off w/ a 9920 and a wound up replacing it w/ the Quark. 9920 is the
minimum you can get away with on a monster. And BTW. Also get yourself an Ultimate BEC while you are at it.
http://www.rc-monster.com/proddetail.php?prod=6vubec Takes a huge load off of the controller. Saves tons of heat. Come to think of it. I dont even think you can use the built in BEC on either of those controllers at 14 cells.
Edit: Besides the load handeling its much smoother on the throtle and brakes than the 9920.