Interestingly enough, Sig now offers both electric and glow versions of a Ready-to-Fly LT-40:

http://www.sigmfg.com/cgi-bin/dpsmar..._20Trainers_01

Nine years old is a good age to start flight training, and a glow trainer should be no problem in a club setting with a flight instructor. Our local clubs will normally provide flight lessons for children eight years or older.

Any of the commercially available flight sims should work fine as a training aid. Real Flight G3.5, Aerofly Professional Deluxe, Reflex XTR, and FS One are all good products. The folks who developed Aerofly Professional Deluxe have a new product out called Easy Fly 2 that sells for $99.99 with radio adapter, or $129.99 with controller. From a pricing standpoint, it's pretty attractive. The graphics and physics are supposed to be straight from the more expensive APD, it simply offers a reduced number of aircraft and flying fields to choose from.

The simulator will help your son (and you) practice in between flight lessons. There are few things more annoying than waiting all week for "training night" at the club when you're learning to solo, and you end up with rain.

A Sig LT-40 Ready-to-Fly package and a good flight simulator should provide you and your son with many years of enjoyment.