Thanks for the input!
I'll probably pick up the single speed eventually, but the two-speed kit is ~100 alone, so I got the RTR. It was more $$$, but I also got a body (for just playing around), servos, and radio (I won't be using an AM radio for anything BL, but maybe for something else). I figure I can get some cash back from the silly .28 engine and other nitro crap on eBay.
I already thought about the BL torque when shifting, but was hoping that if I dialed down the ESC start power (or whatever it would be called), it would help with that. It should also minimize the off-the-line power for less tire spin. Plus, I plan to use the exponential throttle function of my radio to give me a little more off-the-line control (hopefully).
I was concerned that by gearing so high, that the ESC would have trouble getting rotor position at start. Hence another reason for the 2 speed.
We'll see how things go as I build this up.