I need torque, not speed!

[rwinder]

Kind Folks,

New to this hobby, but I love electronics, R/C's and toys.

I have just purchased a Microsizer S2000 (silver, 27 Mhz). It's coming in the mail.

After playing around with it in stock form, I will have an application for this MS that I need some help with. I need it to be slow (fairly) with good run time, and torquey. My son has a wooden train set that needs a powered locomotive that I would love to build. The gauge of the track is very close to the width of the MS, but I will need to do the following (some of these are theoretical, so jump in if I am wrong):

* since the stock MS has a 2.2 motor, I will need a 1.0 (heard it is the slowest and torquiest (is that a word?)
* need to use slightly narrower wheels/tires to exactly match the gauge of the track (gauge is the width between the "rails" of the track, which are actually grooves on the wooden track)
* will need to use the light blue gear set (slowest and torquiest)
* will need to vacuum form a locomotive body and perhaps add false wheels and axle after the drive axle of the MS. I want this to be "live" but not necessarily driven. Two motors may be in the future, but not at this time.
* perhaps add a Pot (potentiometer) to slow down the motor (I read about the Pot modification on this board, Thanks!)

I am using a MS because the track has cross-overs that can utilize the MS steering to go to another part of the track.

What is wrong with my assumptions and what else can I do to make it torquier (other than adding another motor)?

Sorry for the long post, but you guys sound like you know what you are talking about, and thought I would run it by ya'll first.