The Xray M18T is another alternative. It has done very well in National and other top carpet 1/18th events. On carpet you want precision, and the Xray has that in spades. It comes stock with the bellcrank steering which your spending a buttload to obtain through aftermarket options for other manufacturers platforms. It comes with ball diffs and sway bars which also are two important parts for fast and controllable carpet racing.
They also
just released foam tires for it in more than one type of compound, so its ability to be adjusted for each track and temperature has increased exponentially.